1. The register is a1. Simplified unit of a subtractor2. Cascaded group of the flip-flop3. Binary ripple counter4. Data se...
4. Thermo-couple device5. Silicon is having direct band gap1. True2. False3. No gap4. None of these6. Boron is doped in si...
4. Movement of electron-hole pair9. Slope of electrical conductivity Vs temperature in semiconductor is1. Positive2. Negat...
1. Increases2. Decreases3. Remains the same4. Breaks down13. Knee voltage in diode stands for1. Reverse break down voltage...
16. In the zener diode the break down in the reverse characteristic current is due to1. Electrons2. Hole3. Electron hole p...
2. Minimum3. No change4. Zero20. In the transistor the doping at the emitter is much larger than the base results in1. Emi...
23. Clamping circuit is used for1. AC to DC conversion2. Biasing3. Limiting the amplitude4. Wave shaping24. For ideal clip...
2. Minority carrier3. Common collector4. All of the above28. Common emitter configuration is used for a1. Current amplific...
3. Low voltage4. Power rectification32. SCR is based on the principle of1. Voltage regeneration2. Current regeneration3. P...
35. Multiplexer helps in which of the following1. Repetition of similar circuit construction2. Selecting all the signal at...
4. Gray code39. In Johnson code for N bits, the maximum number can be formed is given by an expression1. 2.N b. 2N c. 2N "...
4. All of the above43. Extrinsic semiconductor is1. Doped with impurities2. Exists in the pure state3. N-type only4. Only ...
1. Clock2. Timer3. Event counter4. Multiplier47. Distortion in the amplifier is due to1. Non linearity of the device2. Ind...
1. To increase the selectivity2. To increase the sensitivity3. To increase both selectivity and sensitivity4. To get the d...
54. Slew rate of an OP.amp.is1. Change of O/p voltage with time2. Propagation speed3. Input RC time constant4. Off set vol...
3. Resistance feed back4. Thermistor feed back58. OP.amp. can be converted into capacitor by1. Increasing bandwidth2. Remo...
62. OP.amp. wein bridge oscillator works when the over all gain is1. 180 b. 3 c. 1.2 d. 12563. Important part in a electro...
66. Which of the following device is used as an electronic memory element1. Astable multivibrator2. Monostable multivibrat...
70. Extremely low power dissipation and low cost per gate can be achieved in1. MOS ICs2. CMOS ICs3. TTL ICs4. ECL ICsAnswe...
74. (0.3125)10 when converted to base 8 gives1. (0.16)8 b. (0.26)8 c. (0.24)8 d. (0.124)875. Excess " 3 code is a1. Weight...
78. Which one of the following Boolean identities is correct?1. XYZ + YZ + XZ = YZ + XZ2. XYZ + YZ +XZ = XY + XZ3. XY +XZ ...
82. A micro programmed computer can have the following memories in its control memory unit1. Semiconductor ROM2. Semicondu...
86. The basic RS flip flops is1. A bistable multivibrator2. A monostable multivibrator3. An astable multivibrator4. None o...
3. 45 deg out of phase from the input4. 180deg out of phase from the input90. The equivalent octal number of (492) is1. 57...
1. RAM b. ROM c. PROM d. EPROM95. Large scale Integrated (LSI) circuits usually contain1. Less than 10 gates2. 10 to 100 g...
3. The peak value of the carrier signal4. The average value of the carrier signal100. Microwave (MW) links are generally p...
2. Rsistivity ofGermanium in ohms cm. is approx. equal toa. 50 b. 10-12 c. 50k d. 10-63. The number of free electrons/cubi...
6. The forbidden energy gap for Germanium isa. 1.1eV b. 067eV c. 0.97eV d. 1.7eV7. N type material is formed by the additi...
9. Impurity atoms that produces N type material by its addition in semiconductor is calleda. Donar b. Acceptor c. Conducto...
12. Point contact diodes are preferred at very high frequency, because of its low junctiona. Capacitance and inductanceb. ...
b. OR gatec. Rectifierd. NOR gate15. DC value of a Half wave rectifier with Em as the peak value of the input isa. 0.318Em...
17. If Tc is th e% temperature co of / oC and Vz as zener voltage and T as change in temperature thenthe change in zener v...
c. High frequency operationd. None of these20. Clamping network is the one that will clamp the signal to aa. Different pea...
a. Input signal without distorting the remaining portionb. Input signal with distorting the remaining portionc. Any of the...
23. Ct = K / (Vt + Vr)N where Vt Knee voltage, Vr reverse voltage, K manufacturing dependent constantand N dependent on ty...
26. The shadow mask in colour tube is used toa. Reduce X-Ray emissionb. Ensure each beam hits its own dotsc. Increase scre...
29. Another name for the colour sync in the colour TV systema. Ringing b. Burst c. Damper d. Fly back30. The HV anode supp...
d. A saw tooth current32. In a transistor if Alpha = 0.98, current gain is equal toa. 29 b. 59 c. 69 d. 4933. The active r...
a. Both collector & emitter junction are reverse biasedb. The collector junction is forward biased and emitter junctionc. ...
37. In a simple RC network the bandwidth is equal toa. 1/2 p RCb. RC / 2c. 2 C / p Rd. 2 p / RC38. The time constant of a ...
40. The distortion less output characteristic of a network meansa. Constant amplitude and linear phase shift over frequenc...
42. In an amplitude modulated signal, lower side band frequency is equal to (if the carrier frequency is fcand modulation ...
45. Reactance tube modulator is known fora. FM b. AM c. PPM d. PAM46. Bandwidth and rise time product isa. 0.35 b. 0.45 c....
a. mA b. uA c. nA d. pA50. Cut-in voltage V for silicon is approximatelya. 0.2V b. 0.6V c. 0.9V d. 1.1VAnswersb21. a22. c2...
52. Hall effect with reference to Metal or Semiconductor carrying a current I is placed in atransversemagnetic field B, an...
a. 2 b. 3 c. 4 d. 555. Acceptor impurity is having a valency ofa. 2 b. 3 c. 4 d. 556. Electron volt arises from the fact t...
a. Antimonyb. Arsenicc. Indiumd. Phosphorus58. Excess electron is created bya. Boranb. Galliumc. Indiumd. Arsenic59. A snu...
b. The dv/dt turn onc. L.di/dt of load inductanced. None of these60. Germanium has the valency ofa. 2 b. 3 c. 4 d. 561. Si...
b. Positivec. Neutrald. None of these63. Burst signal in NTSC system is 8 cycles of the frequency ofa. Colour sub carrierb...
c. Front porch of the each vertical sync pulsed. Back porch of the each vertical sync pulse65. The law of mass action with...
c. LC networkd. RC network67. To limit the rate of rise of SCR anode current a smalla. Inductor is inserted in cathode cir...
d. Field voltage and field current69. Proportional Integral controla. Reduces steady state error but reduces the forward g...
c. Improves power outputd. None of theseAnswersb51. a52. c53. b54. b55. b56. b57. c58. d59. b60. c61. c62. b63. a64. a65. ...
c. Magneticd. All the above73. In a line of sight communication the maximum range R in miles between the receiver antenna ...
c. 5 metresd. 2.5 metres75. In standard TV receiving antenna the dipole element isa. 0.5 of the wave lengthb. 0.25 of the ...
d. Diode77. Charge coupled device is an array of capacitors whose structure is similar to:a. Shift registerb. Flip-flopc. ...
d. All of the above79. The typical value of the open loop gain in dB of an amplifier at DC with no feedback is:a. 90 to 10...
81. Rise time of an amplifier is defined as time requireda. To change from 0 to 100 % of its final valueb. To change from ...
83. Tuned amplifier having the frequency range betweena. 150 KHz – 50 MHzb. 100 Hz – 100 KHzc. 100 KHz – 120 KHzd. 50 MHz ...
85. The voltage follower can be obtained using operational amplifiera. Without any feedbackb. Series parallel feedback of ...
87. What would be the output when two input sine waves of frequency 50 KHz and 100 KHz passedthrough an amplifier in the m...
a. Binary additionb. Data transmissionc. Demultiplexingd. Storage of binary information90. Approximately how many number o...
a. Half adderb. Full adderc. Exor gated. AND gate92. Flip flop cannot be called asa. Bistable multivibratorb. 1 Bit memory...
b. To filter out the ripple frequencyc. To increase the current ratingd. To convert AC into DC94. Binary equivalent of the...
b. ANDc. NANDd. EXOR96. Which of the following definition is true in the De Morgan’s theorema. Multiplication symbols are ...
c. 10101001d. None of these98. Combinational circuit are mainly characterized bya. Output depends upon the previous state ...
c. It will respond to input and it is a basic memory elementd. All of the above100. Four bit code is calleda. Nibbleb. Byt...
1. The gray code equivalent of binary 1100 isa. 1011 b. 1101 c. 1010-and d. 11002. A Multiplexer hasa. Multiple inputs and...
a. Adds two binary digits and produces their sum and carry-ansb. Adds half the sum to the carryc. Adds two binary digits a...
a. RAM-ans b. ROM c. EPROM d. Magnetic tape6. Barrier voltage in a P-N junction is caused bya. Thermally generated electro...
9. The noise figure of an ideal amplifier in decibel isa. 0.5 b. 0-ans c. 1 d. 1010. The rise time of an amplifier is 200 ...
12. A device which behaves like SCRs isa. UJT b. Triac-ans c. MOSFET d. SRD13. A plate modulated class C RF amplifier prod...
b. Its temperaturec. Both value and temp-ansd. None of these16. A 32 channel 8 bit PCM system samples at 8 KHz rate. The o...
18. A half wave folded dipole has a radiation resistance ofa. 72 W b.50W c. 144W d. 288W-ans19. Top loading is used in ant...
c. Lowest frequency reflected by the Ionosphere at vertical incidenced. Lowest communication frequency possible21. The cat...
a. Via the ionosphereb. Along the ground-ansc. Through the troposphered. By reflection in ionosphere25. The impedance of a...
a. 0.25 b. 0.5 c. 75-ans d. 028. Microwave repeaters are typicallya. 25 b. 50-ans c. 75 d. 100 Kms apart29. To overcome fa...
31. A duplexer is used toa. Receive two signals in one antennab. Prevent interference between two antennac. Mix two signal...
33. A rectangular waveguide behaves like a filter ofa. Band pass b. High pass-ans c. Low pass d. Band stop34. The signal p...
36. For the national TV and ratio network, INSAT-IB usesa. 400MHz b. 2.5GHz c. 2.5 and 5GHz d. 4 and 6 GHz-ans37. A typica...
c. Modulating and demodulating signals sent on a line-ansd. Suppressing noise interference39. The most effective anti-jamm...
d. Magnetics41. Monopulse technique is used ina. Radar-ansb. Radio relayc. Data communicationd. Fibre-optics42. HDLC is a ...
d. Error checking43. A gatewaya. Is a place where radars are connectedb. Permits dissimilar networks to communicate-ansc. ...
45. If several stations in a network want to use a single channel without interfering with one another,the technique used ...
d. Aluminium deposition47. ICs made by sputtering of materials on a ceramic substrate are calleda. Monolithic b. Hybrid c....
a. 10cm b. 30cm c. 3cm d. 1cm51. Which of the following microwave tubes can be considered as broad band devicesa. Magnetro...
b. Small sizec. Low power consumptiond. Low input impedance54. What is the resolution of 8 bit A/D converter if its full s...
57. The device used for isolating the transmitter and receiver in a radar system is calleda. Diplexerb. Duplexerc. Directi...
59. The advantage of Totem pole output stage in TTL ICs isa. Low output impedanceb. Can sink more currentc. Oscillations a...
b50. b51. d52. b53. c54. c55. b56. c57. b58. b59. a60. a61. Electron volt is equivalent toa. 3.8 * 10-20 ergb. 1.602 * 10-...
d. Surface conditions of the surface63. Flux is expressed in radio-metric system ina. Lumensb. Photonsc. Wattsd. Candles64...
65. Energy stored in a capacitor as a function of voltage is given bya. CV2b. 1V2/2Cc. ½ CV2d. 1V/2C66. The operational am...
68. A radar transmits a peak power of 100 KW with pulse width of 1 m sec and a pulse repetition rate of100 KHz. The averag...
c. Light house tubed. Traveling wave tubeAnswers61. b62. b63. a64. b65. c66. d67. c68. b69. d70. a71. a72. a73. b74. a75. ...
73. In frequency modulation the maximum permissible modulation index isa. Unity b. 50 c.1000 d. no limit74. In FM transmis...
76. The usage of micro sec for defining emphasis is a standard practice but this micro sec definitionmeansa. 3 dB point of...
78. Selectivity meansa. Bandwidthb. Gainc. Modulation indexd. None of these79. Narrow bandwidth broadcast reducesa. The qu...
80. Squelch means keeping the receivera. ON in the absence of carrierb. OFF in the absence of carrierc. To remove AGCd. In...
83. A broadcast radio transmitter radiates 10 KW power when modulation is 60%. Its carrier power willbea. 8.47KW b.8.92KW ...
a. Ö m12/m22b. Ö m1 m2c. Ö m12+m22d. Ö m22/m1287. If it is transmitted current and Ic is transmitter current at zero modul...
a. (Rr - Rd) / (Rr + Rd)b. (Rr + Rd) / (Rr – Rd)c. Rr / (Rr + Rd)d. Rd / (Rr + Rd)89. In end fire array, the currenta. Mag...
a. Magnitude and phase in each element is the sameb. Magnitude is the same but phase is differentc. Magnitude is different...
b. 2Ö [m/a]2 + [n/b]2c. Ö(m/a)2 + (n/b)2 /2d. Ö [m/a]2 + [n/b]293. For the standard rectangular waveguide dimension of 4*2...
95. Which of the following statement is truea. Tunnel diode & IMPATT diode are negative resistance devicesb. Tunnel diode ...
97. In SSB modulation the modulation index is increased from 0.5 to 1.0, then the power will beincreased bya. 2 times b. 4...
c. Decrease voltage gaind. Decrease current gain100. The transfer function of the system shown isa. G(s) / {1 + H(s)}b. G(...
1. In which of the following movements ‘Vande Mataram’ was adotped for the first time as a slogan foragitation?(A) Revolt ...
(D) Mohammad Ali Jinnah3. Which one of the following is not correct about the Congress Session.of Lucknow, 1916?(A) Ambika...
(B) Non-cooperation Movement(C) Communist Movement(D) Revolutionary Movement5. In India “Currency Notes issue system” is b...
(A) Persons with no jobs(B) Unemployment among house wives(C) Unemployment among per sons above 60 years pf age(D) Employm...
Codes:(A) 1 only(B) 1 and 2 only(C) 1,2and3only(D) 2, 3 and 4 only8. ‘SIDBI’ has been established to-(A) Finance small sca...
9. Gangubai Hangal, who died a few months ago, was a?(A) Classical singer(B) Dancer(C) Painter(D) Sitar player10. Deep Jos...
(D) Emergent leadership11. The missing number in the following series: 5,10,13,26,29, 58, 61,…Is?(A) 122(C) 128(B) 125(D) ...
(C) Rs. 500(D) Rs. 2,00013. Which one of the following expresses error in computer data?(A) chip(B) byte(C) bug(D) bit14.A...
(A) Both (A) and (R) are true and (A) is the correct explanation of (A)(B) Both (A) and (A) are true but (H) is not the co...
16. The professional printed circuit board generally use the following as the raw material:1.Paper base bakelite copper cl...
4. It is very hard and does not wear off18. A resistance of approximate value 85W is to be measured by using an ammeter of...
a. .3      b. 1      c. 0.67       d. 0.3320. It is proposed to fabricate a simple Ohm meter for measuring resistor values...
22. For the circuit shown, the maximum power is delivered to the load resistance RL when the value ofRg isa. 2 ohms      b...
2. X2 + X - 1 = 03. X2 + X + e = 04. X2 + X – e = 025. The Laplace transform of the function f(t) = cos wt is1. w/(s2 + w2...
3. w2/(s2 + w2)4. s/(s2 + w2)26. If a = b = c, one value of X which satisfies the equation=0 is given bya. x=a      b. x=b...
1. Q r [LC]1/22. ½ rp r [LC]1/23. – Q r[LC]1/24. Q r [LC]1/228. A battery eliminator is required to be constructed and an ...
2. Half wave rectified3. Bridge rectifier4. None29. Chokes used in rectifier filter circuits are wound on a core with a sm...
a.. 0.1 V rms   b. 0.1 mV    c. 100 mV     d. 1.0 V rms Here are the details of 2011 BEL Placement Paper - II job in Bhara...
2. The earliest coins of India were made of ?(A) Copper(B) Gold(C) Lead(D) Silver3. The Mongols appeared for the first tim...
(D) Razia4. The first woman ruler of medieval India was?(A) Chand Bibi(B) Durgavati(C) Noorjahan(D) Razia5. The Moplah Reb...
(B) Marathawada(C) Telengana(D) Vidarbha6. Which part of the Constitutions of India has been described as the: Soul of the...
(A) Uttar Pradesh(B) Rajasthan(C) Gujarat(D) Karnataka8. Who has the right to seek advisory opinion of the Supreme Court o...
9. Consider the following statements about the Governor of a State1. He is appointed by the President.2. He holds office a...
(A) Ahmedabad—Sabarmati(B) Lucknow —Gomti(C) Bhubaneshwar—Mahanadi(D) Ujjain-Shipra11. Dilwara Jain temple is situated at?...
12. Which one of the following is the biggest shipping canal in the world?(A) Kiel Canal(B) Panama Canal(C) Soo Canal(D) S...
(D) Bengal14. Who was the first Vice-President of India?(A) Dr. S. Radhakrishnan(B) Dr. Rajendra Prasad(C) C. V. Raman(D) ...
(B) Frustration in soldiers(C) Failure of British Government(D) Administrative research16. For VHF interfering waves gener...
1. Smaller at night than in the day time2. Larger at night than in the day time3. Same at night and in the day time4. A ma...
a. 1.5 V/m           b. 2.115 V/m      c. 3.0 V/m   d. 6.0 V/m20. The directive gains of non-resonant and resonant wire an...
1. Radiation resistance2. Power gain of the antenna3. Physical area of the antenna4. Wavelength, assuming other parameters...
24. Narrow trigger pulses are required to be generated from a square wave pluse train (pulse width =T). The linear wave sh...
26. In the circuit shown below. if R = 0 and S = 1, the outputs Q and Q will be1. Q low, Q high2. Both low3. Q high, Q low...
3. Higher drive capability4. Higher noise-immunity28. For a reverse-biased PN junction. If the applied voltage is doubled ...
4. Large output power30. A pulse train has the following characteristics:Peak amplitude = 10 V, Pulse ON time 1 secPulse O...
TECHNICAL (100M)ENG +APTI+REASONING (100M)1.Ghost interference in TV is Due to?2. which of the following frequency is not ...
10.for maximum power transfer theorem |ZL|=?11.one question on capacitor filter, rectifier circuit ?12. three questions on...
22. group of 4-bits used in nibble23. number of address lines required for 4096x12 ROM..........24.volatile memory ..........
. Transition capacitance Ct of a Varicap diode with Knee voltage Vt, reverse voltage Vr and K, theconstant based on semico...
c. 1/2d. 1/4                    Answer : c3. The distortion less output characteristic of a network meansa. Constant ampli...
c. One side bandd. None of these                    Answer : b5. In an amplitude modulated signal, lower side band frequen...
1. Excess noise generated2. Bandwidth of the receiver3. Gain of the receiver4. Operating frequencyAnswer :17. The ratio re...
8. In an amplitude modulation system, the modulation index is dependent upon:1. Modulating frequency only2. Carrier amplit...
Answer : 310. The value of a resistor creating thermal noise is doubled. The noise power generated is therefore:1. Halved2...
Answer : a12. In JFET, the drain current Id is given by (Idss drain – source saturation current Vgs – Gate – sourcevoltage...
c. Increase screen brightnessd. Provide degaussing for the screenAnswer : b14. Indicate which of the following signal is n...
b. Burstc. Damperd. Fly backAnswer : d16. Another name for the colour sync in the colour TV systema. Ringingb. Burstc. Dam...
17. The HV anode supply for a picture tube of a TV receiver is generated in thea. Mains transformerb. Vertical output stag...
19. In a transistor if Alpha = 0.98, current gain is equal toa. 29b. 59c. 69d. 49Answer : d20. The active region in the co...
d. Both collector & emitter junction are forward biasedAnswer : c21. The saturation region in the common emitter configura...
c. 30%, 11%, 50%d. 33.3%, 33.5%, 38.3%Answer : a23. Equalizing pulse width, if H is the Horizontal sync ratea. 0.64 Hb. 0....
a. 1/2 p RCb. RC / 2c. 2 C / p Rd. 2 p / RCAnswer : a25. The time constant of a RC network is given bya. RCb. C/Rc. R/Cd. ...
26. First zero crossing of pulse frequency spectrum occurs at if d is the pulse width, T is the pulserepetition ratea. 1/d...
Answer : 228. If the carrier of a 100 percent modulated AM wave is suppressed the percentage power saving willbe:a. 50b. 7...
4. Carrier and a number of side bandsAnswer : 330. The frequency deviation in FM system is proportional to:1. Modulating f...
2. Dependent on modulating frequency3. Dependent on modulating index4. Independent of the aboveAnswer : 432. A quarter wav...
1. Another open circuited line2. Another short circuited line3. Quarter wave transmission line4. Half wave transmission li...
35. The component generally used to sample a portion of the energy transmitted in a line is1. Isolator2. Circulator3. Dire...
Answer : 237. The antenna can be considered as1. Matching the source and free space2. Matching the source to the line3. Ma...
3. 377 W4. 50 WAnswer : 339. The polarization refers to1. The physical orientation of the radiated wave2. The directional ...
b. Öu/ec. Öe/ud. ÖeuAnswer : 241. The power density at distance ‘r’ from an isotropic radiator with transmitted power P is...
42. The carrier in an FM system disappears for the lowest modulation index of:a. 0.5b. 1.0c. 2.4d. 3.5Answer : c43. The di...
44. The overall noise figure of two cascaded amplifiers is equal to1. The algebraic sum of the two2. The sum of the square...
4. KTo / FGAnswer : 146. The effective noise temperature of an amplifier is equal to1. (F + 1) To2. FTo3. (F – 1) To4. Non...
3. Its operating frequency4. None of these                     Answer : 448. The velocity of electromagnetic wave in a coa...
1. Is proportional to the load impedance2. Is dependent on the source impedance3. Is a mis-match between the load and line...
51. The standing wave voltage node along a line repeats at the rate of if L is the wave lengtha. L/4b.L/2c.Ld.2LAnswer : 2...
4. FM index less than or equal to 1Answer : 353. S/N improvement of FM over AM, B is the FM modulation indexa. 3B2b.Bc.2Bd...
3. Single side band4. None of theseAnswer : 255. Sound transmission in TV employ1. Amplitude modulation2. Phase modulation...
1. Reactance FET modulator2. Varacter divide modulator3. Amstrong modulator4. Reactance bipole transistor modulatorAnswer ...
58. The isotropic antenna is represented by1. Dipole antenna2. Rhombic antenna3. Yagi uda antenna4. No such antenna exists...
Answer : 260. The parabolic reflector antenna are generally used to1. Provide high gain2. Provide pencil beam3. Increase b...
4. Allow the feed to be placed at a convenient pointAnswer : 462. A helical antenna is used for satellite tracking because...
2. Used as a radar receiving antenna3. Circularly polarized like other circular antenna4. Useful as a VHF receiving antenn...
1. Is greater than in free space2. Depends only on the waveguide dimensions and the free-space wavelength3. Less than the ...
67. The velocity of propagation (group velocity) in a waveguide is1. Less than the free space velocity2. Greater than the ...
Answer :369. The dominant mode in a rectangular waveguide isa. TE11b. TE10c.TE20d.TM11Answer : 270. The characteristic wav...
3. Is same as the free space impedance4. None of theseAnswer : 171. A choke flange may be used to couple two waveguides1. ...
2. Sky waves3. Surface waves4. Space wavesAnswer : 473. As electromagnetic waves travel in free space, only one of the fol...
74. High frequency waves are1. Absorbed by the F2 layer2. Reflected by the D layer3. Affected by the solar cycle4. Capable...
76. When microwave signals follow the curvature of the earth, this in known as1. Faraday effect2. Ducting3. Ionospheric re...
4. Acts as an antenna arrayAnswer : 478. One of the following consists of non-resonant antenna:1. The folded dipole2. The ...
3. A circuit element to connect unbalance line to unbalanced line4. None of theseAnswer : 180. The slotted line is used to...
1. Ecm/22. Ecm3. Ec/m4. 2Ec/mAnswer : 182. The dominant mode in a circular waveguide isa. TE01b.TE11c.TM01d.TM11          ...
83. A ferrite is1. A non-conductor with magnetic properties2. An inter metallic compound with particularly good conductivi...
4. Gyro magnetic resonanceAnswer : 185. The isolator is1. Bidirectional2. Unidirectional3. Used to tap the power in a wave...
3. To protect the antenna4. To avoid arcing in waveguidesAnswer : 187. A TR tube is used1. To protect the high power trans...
1. TWT amplifier2. Klystron oscillator3. Magnetron oscillator4. Cross field amplifiersAnswer : 389. The gain bandwidth pro...
90. The cavity magnetron uses strapping to1. Prevent mode jumping2. Prevent cathode-back heating3. Ensure bunching4. Impro...
Answer : 292. One of the following is not used as a microwave mixer or detector1. Crystal diode2. Schottky – barrier diode...
4. Oscillators at millimeter frequenciesAnswer : 294. Surface acoustic waves propagate in:1. Gallium arsenide2. Indium pho...
2. Degenerate amplifier3. Lower-side band up converter4. Upper-side band up converterAnswer : 296. The negative resistance...
1. Because of atmospheric attenuation2. Because of output tube power limitations3. Because of Earth’s curvature4. To ensur...
99. A geostationary satellite1. Is motionless in space(except for its spin)2. Is not really stationary at all, but orbits ...
Answer : 2101. After a target has been acquired the best scanning system for tracking is1. Nodding2. Spiral3. Conical4. He...
3. Moves perpendicular to the beam4. Does not depend on the target velocityAnswer : 1103. The Doppler effect is used in (i...
3. Use monopulse4. Use MTIAnswer : 2105. The A-scope displays1. Target position and range2. Target range but not position3...
a. 3.58b.4.5c. 45.75d. 5.58Answer : a107. In television 4: 3 : represents1. The interlace ratio2. The maximum horizontal d...
108. Equalizing pulses in TV are sent during the:1. Horizontal blanking2. Vertical blanking3. The serrations4. Horizontal ...
Answer : 2110. The number of frames in Indian TV system is:a. 50b. 60c. 25d.30Answer : a111. In a TV receiver the colour k...
4. Makes sure that the colour burst is not mistaken for sync pulsesAnswer : 1112. A parametric amplifier must be cooled1. ...
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  1. 1. 1. The register is a1. Simplified unit of a subtractor2. Cascaded group of the flip-flop3. Binary ripple counter4. Data selector2. The energy of the photo electron depends upon the following factor1. Intensity of incident radiation2. Quality of the photocathode3. Frequency of incident radiation4. Type of the incident light source3. Hall effect is used to determine1. Magnetic flux2. Current density3. Type of semiconductor material4. All of the above4. Which one of the following is the thermistor1. Semiconductor device2. Microwave device3. Platinum resistance thermometer
  2. 2. 4. Thermo-couple device5. Silicon is having direct band gap1. True2. False3. No gap4. None of these6. Boron is doped in silicon to form1. P-type2. N-type3. Intrinsic4. None of these7. The concentration of impurity in doped silicon semiconductor per atom is1. 1018 b. 1022 c.108 d.10-228. Conduction in P-type semiconductor is due to1. Movement of hole2. Movement of electron3. Movement of atoms
  3. 3. 4. Movement of electron-hole pair9. Slope of electrical conductivity Vs temperature in semiconductor is1. Positive2. Negative3. Linear4. No effect10. Volt equivalent of temperature of silicon at room temperature (300 deg K) is1. 0.7V b. 1.1V c. 0.026V d. 16VAnswer1. b2. c3. d4. d5. a6. a7. a8. a9. b10.11. Carbon is not used as semiconductor because1. It does not belong to silicon group2. It is a good conductor3. It is not a conductor4. Band gap is very high12. In forward bias of P-N junction depletion region
  4. 4. 1. Increases2. Decreases3. Remains the same4. Breaks down13. Knee voltage in diode stands for1. Reverse break down voltage2. Saturation voltage3. Threshold of current conduction4. Peak inverse voltage14. An ideal semiconductor diode for an AC input acts like1. Unidirectional switch2. Bidirectional switch3. Cuts off AC part4. Power booster15. Reverse saturation current in P-N junction diode is due to1. Hole conduction2. Electron conduction3. Minority carrier conduction4. Majority carrier conduction
  5. 5. 16. In the zener diode the break down in the reverse characteristic current is due to1. Electrons2. Hole3. Electron hole pair4. Crystal ions17. The percentage of voltage regulation is defined as1. V no load " V load r100 / V load2. V load " V no load r100 / V load3. V load " V no load r100 / V no load4. V no load r100 / V load18. Filtering is effected by shunting the load with a1. Capacitor2. Resistor3. Inductor4. None of these19. Without applying the biasing voltage the transistor current would be1. Maximum
  6. 6. 2. Minimum3. No change4. Zero20. In the transistor the doping at the emitter is much larger than the base results in1. Emitter current entirely of holes2. Emitter current entirely of electrons3. Base current is due to electron-hole pair4. Emitter does contribute carrier which can reach collectorAnswersc11. b12. b13. c14. a15. c16. c17. a18. a19. b20.21. The largest current carrying component in P-N-P transistor is1. Electrons2. Holes3. Electron hole pair4. Silicon atoms22. The circuit shown in the figure represents1. Rectifier2. Clamping circuit3. Clipping circuit4. Low pass filter
  7. 7. 23. Clamping circuit is used for1. AC to DC conversion2. Biasing3. Limiting the amplitude4. Wave shaping24. For ideal clipping circuit one should use a diode with cut-in voltage1. 0.7V b.1.1V c. 0V d. 0.2V25. The ratio of peak inverse voltage of full wave and half wave rectifier is1. 1 b. 2 c. 1/2 d. 1/426. Which of the following transistor configuration is a power amplifier1. Common emitter2. Common base3. Common collector4. All of the above27. In a active mode of a transistor, collector conduction takes place due to1. Majority carrier
  8. 8. 2. Minority carrier3. Common collector4. All of the above28. Common emitter configuration is used for a1. Current amplification2. Voltage amplification3. Current and voltage amplification4. Charge amplification29. The transistor configuration where input is emitter and output is collector is called:1. Common emitter2. Common base common collector3. Voltage follower(current gain)30. Beta of a transistor is given by1. Ib/Ic b. Ic/Ib c. Ib/Ie d. Ic/IeAnswersb21. b22. b23. c24. b25. a26. d27. a28. c29. b30.31. Germanium transistor is preferred over silicon transistor in the following application1. High frequency2. High power
  9. 9. 3. Low voltage4. Power rectification32. SCR is based on the principle of1. Voltage regeneration2. Current regeneration3. Power regeneration4. Power rectification33. The number of clock pulses arriving at the digital counter input, should be in the form of1. Decimal2. Binary3. Octal4. Hexadecimal34. In which of the counter the clock input is common to all flip flops1. Asynchronous counter2. Synchronous counter3. Decade counter4. Down counter
  10. 10. 35. Multiplexer helps in which of the following1. Repetition of similar circuit construction2. Selecting all the signal at the output at the same time3. Prevention of constructing similar circuits4. Increase in the constructional costs due to repetition circuits36. Full adder for two inputs can be developed with the help of1. Two half adder on OR gate2. One half adder and two OR gate3. An EXOR gate and AND gate4. Two AND gates and an OR gate37. The important use of gray code is for a1. Ripple counter2. Full adder3. Encoder4. Decoder38. In which of the code only one bit changes at each time1. BCD2. Aiken code3. Excess 3 code
  11. 11. 4. Gray code39. In Johnson code for N bits, the maximum number can be formed is given by an expression1. 2.N b. 2N c. 2N " 2N d. None of these40. The active mode of transistor operation is used in log circuits because of its1. Non linearity2. Linearity3. Switching nature4. High speedAnswersb31. b32. c33. b34. b35. a 36. a37. c38. d39. b40. a41. Intermediate frequency in television receiver is1. 26-46 MHz2. 1.6-2.3 MHz3. 455-KHz4. None of these42. At absolute temperature, a silicon crystal acts like an insulator because1. Electrons cannot move through a crystal2. Electrons are tightly held by other atoms3. Electrons can break away only by supplying energy
  12. 12. 4. All of the above43. Extrinsic semiconductor is1. Doped with impurities2. Exists in the pure state3. N-type only4. Only P-type44. The process of extracting the audio information from the modulated envelope is called1. Modulation2. Detection3. Transmission4. Oscillation45. Selectivity of a radio receiver is defined as1. Ability to reproduce the original frequencies2. Ability to eliminate wanted frequencies3. Ability to reject unwanted frequencies4. Ability to pick up the weak signal46. Digital counter cannot be used as
  13. 13. 1. Clock2. Timer3. Event counter4. Multiplier47. Distortion in the amplifier is due to1. Non linearity of the device2. Inductance presents in the circuits3. Capacitance4. Stray effect48. The purpose of RF amplifier tuning in the radio receiver is1. To reject all the frequencies2. To select all the frequencies3. Only to select required frequencies & amplification4. To vary the band width49. The intermediate frequency used in the radio receiver is1. 455KHz b. 1.6 MHz c. 20 MHz d. 60 MHz50. The purpose of using tuned circuit between stages in the radio receiver is
  14. 14. 1. To increase the selectivity2. To increase the sensitivity3. To increase both selectivity and sensitivity4. To get the detector outputAnswers41. d42. d43. a44. b45. c46. d47. a48. c49. a50.51. In an amplifier, the frequency characteristic may be divided into how many regions1. Two b. Three c. Four d. Zero52. Op.amp. has high input impedance because1. High band width2. Differential amplifier3. Current source at input end4. Common collector configuration53. Gain of an OP amp. In inverting mode is "Rf / Rn provided, the OP.amp. has1. Low output impedance2. Low input bias current3. High CMRR4. High open loop gain
  15. 15. 54. Slew rate of an OP.amp.is1. Change of O/p voltage with time2. Propagation speed3. Input RC time constant4. Off set voltage drift55. Instrumentation OP.amp. is used in application where1. Two instrument are to be interfaced2. Input is very low level signal3. DC signals are involved4. Differential signals are involved56. An OP.amp. integrater will be1. Capacitor at input2. Diode at input3. Diode feed back4. Capacitor feed back57. A logarithmic amplifier will have1. Inductor feed back2. Diode feed back
  16. 16. 3. Resistance feed back4. Thermistor feed back58. OP.amp. can be converted into capacitor by1. Increasing bandwidth2. Removing feed back3. Increasing input impedance4. Positive feed back59. Comparators are used as1. Switching device2. Linear amplifiers3. Power amplifiers4. High speed amplifiers60. Typical output impedance of 741 OP amps. is1. 0.5 W b. 1 K W c. 1 W d. 75 WAnswers51. c52. b53. d54. b55. b56. d57. d58. a59. a60. a61. Typical unity gain bandwidth of 741 OP amps. is1. 10 MHz b. 100 KHz c. 1 MHz d. 1.5 MHz
  17. 17. 62. OP.amp. wein bridge oscillator works when the over all gain is1. 180 b. 3 c. 1.2 d. 12563. Important part in a electronic voltage regulator is1. Error amplifier2. External pass transistor3. Reference voltage diode4. All the above64. To generate a triangular wave form from a square wave1. Differentiator is used2. Integrator is used3. Logarithmic amplifier is used4. Clipping circuit is used65. For multiplying two analog signals which one of the following is used1. Comparator2. Hall effect device3. Gunn diode4. Tunnel diode
  18. 18. 66. Which of the following device is used as an electronic memory element1. Astable multivibrator2. Monostable multivibrator3. Magnetic tape4. None of these67. Phase sensitive detector in lock-in-amplifier is used1. To increase the sensitivity of an instrument2. To limit the bandwidth3. To increase the dynamic range of the signal4. To increase the input impedance68. In television transmission video signal is1. Frequency modulated2. Amplitude modulated3. Phase modulated4. delta modulated69. The Boolean function XYZ + YZ + XZ, after simplification gives1. X b. Y c. Z d. X+Y+Z
  19. 19. 70. Extremely low power dissipation and low cost per gate can be achieved in1. MOS ICs2. CMOS ICs3. TTL ICs4. ECL ICsAnswersc61. a62. b63. d64. b65. a6. c7. b68. b69. c70. b71. Which of the following digital IC families can give maximum fan-out1. ECL b. PMOS c. HTL d. CMOS72. A punched card has1. 22 rows, 90 columns2. 12 rows, 80 columns3. 12 rows, 2 columns4. 8 rows, 128 columns73. Which one of the following is a 16 bit microprocessor1. Zilog 802. Intel 80853. Motorola 68004. Intel 8086
  20. 20. 74. (0.3125)10 when converted to base 8 gives1. (0.16)8 b. (0.26)8 c. (0.24)8 d. (0.124)875. Excess " 3 code is a1. Weighted code2. Cyclic code3. Error correcting code4. Self complementing code76. ASC II code is a1. Error detecting code2. Self correcting code3. An alphanumeric code4. A weighted code77. Modulo " 2 addition is represented by1. f = XY + XY2. f = XY + XY3. f = X + XY4. f = XY + XZ + YZ
  21. 21. 78. Which one of the following Boolean identities is correct?1. XYZ + YZ + XZ = YZ + XZ2. XYZ + YZ +XZ = XY + XZ3. XY +XZ = XY + XZ + YZ4. X + XY = XY79. SN7410 IC is a1. Quad 2 input NAND gate2. Triple 3 input NAND gate3. Dual M/S J-K flip flop4. None of these80. Intel 8085 microprocessor has two registers known as primary data pointers these are1. Registers V & C2. Registers D & E3. Registers H & L4. None of these81. Intel 8080 microprocessor has an instruction set of 91 instructions. The op-code to implement theinstruction set should be at least1. 6 bit b. 7 bytes c. 7 bit d. 8 bit
  22. 22. 82. A micro programmed computer can have the following memories in its control memory unit1. Semiconductor ROM2. Semiconductor RAM3. Magnetic RAM4. None of these83. In digital circuits parallel operation is preferred because1. It requires less memory2. Circuitry is simple3. It is faster than series operation4. For None of these of the above reasons84. SN 7401 IC is a1. Quad 2 input NAND gate2. Quad 2 input NAND gate with open collector output3. Quad single input NAND gate with open collector output4. None of these85. What is the binary code of (26)?1. 11001 b. 10001 c. 11010 d. 10100
  23. 23. 86. The basic RS flip flops is1. A bistable multivibrator2. A monostable multivibrator3. An astable multivibrator4. None of these87. The input impedance of an operational amplifier is1. Very small2. Zero3. Very high but not infinite4. Infinite88. Sn 7411 is1. OP.amp. monolithic and short circuit protection in-built2. Two input NAND gate3. Three input NAND gate with open collector output4. None of these89. The output voltage of an operational amplifier is1. 90 deg out of phase from the input2. 90 deg out of phase from the input
  24. 24. 3. 45 deg out of phase from the input4. 180deg out of phase from the input90. The equivalent octal number of (492) is1. 574 b. 547 c. 754 d. 758Answers71. d72. b73. d 74. c75. d76. c77. a78. c79. b80. c81. c82. a83. b84. b85. c86. a87. c88. c89. d90. c91. The equivalent decimal number for gray code 1011 is1. 14 b. 13 c. 41 d. 3192. The output will be only if all inputs go to 1 in case of1. OR gate b. AND gate c. NAND gate d. NOT gate93. Which of the following circuits is known as half adder?1. AND circuit2. OR circuit3. Exclusive OR circuit4. None of these94. Which of the following memories is used to store variable quantities of the data?
  25. 25. 1. RAM b. ROM c. PROM d. EPROM95. Large scale Integrated (LSI) circuits usually contain1. Less than 10 gates2. 10 to 100 gates3. more than 100 gates4. more than 1000 gates96. The Boolean expression A + AB + B on simplification can be reduced to:1. 0 b. 1 c. A + B d. A + B97. For realizing a decade counter using flip-flops the minimum number of flip-flops required is1. 4 b. 5 c. 6 d. 1098. Which logic family is widely used in SSI & MSI applications?1. ECL b. DTL c. TTL d. None of these99. An amplitude modulation detector detects1. The peak value of the modulation signal2. The envelop of the modulation signal
  26. 26. 3. The peak value of the carrier signal4. The average value of the carrier signal100. Microwave (MW) links are generally preferred to coaxial cable for TV transmission because:1. They have less overall phase distortion2. They are cheaper3. Of their greater bandwidth4. Of their relative immunity to impulse noise.91. b92. b93. c94. a95. c96. b97. a98. c99. b100. a(Technical-Electronics-IInd)1. Resistivity of silicon in ohms cm. is approx. equal toa. 50 b. 1012 c. 230k d. 10-6
  27. 27. 2. Rsistivity ofGermanium in ohms cm. is approx. equal toa. 50 b. 10-12 c. 50k d. 10-63. The number of free electrons/cubic cm intrinsic Germanium at room temperature is approx. equal toa. 1.5*1010 b. 2.5*1013 c. 1000 d. 5*1064. The number of free electrons/cubic cm of intrinsic silicon at room temperature is approx. equal toa. 1.5*1010 b. 2.5*1013 c. 10000 d. 5*1065. The forbidden energy gap for silicon isa. 1.1eV b. 067eV c. 0.97eV d. 1.7eV
  28. 28. 6. The forbidden energy gap for Germanium isa. 1.1eV b. 067eV c. 0.97eV d. 1.7eV7. N type material is formed by the addition of the following (penta valent )atom in n to semiconductormateriala. Antimonyb. Arsenicc. Phosphorousd. Any of the above8. P type material is formed by the addition of the following [Trivalent] atom tn to semiconductormateriala. Boron b. Gallium c. Indium d. Any of the above
  29. 29. 9. Impurity atoms that produces N type material by its addition in semiconductor is calleda. Donar b. Acceptor c. Conductor d. Insulator10. Impurity atoms that produces P type material by its addition in semiconductor is calleda. Donar b. Acceptor c. Conductor d. Insulator11. Dynamic resistance of a diode Rd is if voltage changes is DVd and the current change is D Ida. D Vd / D Idb. D Id / D Vdc. 1 / DVdd. 1 / D Id
  30. 30. 12. Point contact diodes are preferred at very high frequency, because of its low junctiona. Capacitance and inductanceb. Inductancec. Capacitance13. Identify the circuit given belowa. AND gateb. OR gatec. Rectifierd. NOR gate14. Identify the circuit given belowa. AND gate
  31. 31. b. OR gatec. Rectifierd. NOR gate15. DC value of a Half wave rectifier with Em as the peak value of the input isa. 0.318Emb. 0.418Emc. 0.518Emd. 0.618Em16. Change in Zener voltage of 10V at 100o C if temperature co-efficient is 0.072%o C asa. 0.54 V b. 0.74 V c. 0.64 V d. 0.14 V
  32. 32. 17. If Tc is th e% temperature co of / oC and Vz as zener voltage and T as change in temperature thenthe change in zener voltage isc. 100. Vz. Tc DTd. None of these of the above18. PIV for a full wave rectifier, if Em is the peak voltage isa. Em b. 1.5Em c. 0.636Em d. 2Em19. Schottky Barrier diodes becomes important ata. DC level operationb. Low frequency operation
  33. 33. c. High frequency operationd. None of these20. Clamping network is the one that will clamp the signal to aa. Different peak valueb. Different DC levelc. Different polarity leveld. Different RMS levelAnswers1. c2. a3. a4. b5. a6. b7. d8. d9. a10. b11. a12. c13. b14. a15. a16. a17. a18. d19. c2021. Clipping network is the one that will clip a portion of the
  34. 34. a. Input signal without distorting the remaining portionb. Input signal with distorting the remaining portionc. Any of the aboved. None of these22. Transition capacitance Ct of a Varicap diode with Knee voltage Vt, reverse voltage Vr and K, theconstant based on semiconductor material and the construction technique & N dependent on type ofjunction is given bya. 1 / K (Vt + Vr)N/2b. 1 / K (Vt + Vr)Nc. K / (Vt + Vr)Nd. K / (Vt + Vr)1/N
  35. 35. 23. Ct = K / (Vt + Vr)N where Vt Knee voltage, Vr reverse voltage, K manufacturing dependent constantand N dependent on type of junction, for alloy junction the value of N isa. 1/3 b. 2/3 c. 1/2 d. 1/424. Ct = K / (Vt + Vr)N where Vt Knee voltage, Vr reverse voltage, K manufacturing dependent constantand N dependent on type of junction, for diffused junction the value of N isa. 1/3 b. 2/3 c. 1/2 d. 1/425. In JFET, the drain current Id is given by (Idss drain – source saturation current Vgs – Gate – sourcevoltage, Vp the pinch off voltage)a. Idss[1 – Vp/Vgs]b. Idss(1 – Vgs/Vp)2c. Idss[1 – Vgs/Vp)d. Idss(1 – Vgs/Vp)3/2
  36. 36. 26. The shadow mask in colour tube is used toa. Reduce X-Ray emissionb. Ensure each beam hits its own dotsc. Increase screen brightnessd. Provide degaussing for the screen27. Indicate which of the following signal is not transmitted in colour TVa. Y b. Q c. R d. I28. Another name for horizontal retrace in TV receiver is thea. Ringing b. Burst c. Damper d. Fly back
  37. 37. 29. Another name for the colour sync in the colour TV systema. Ringing b. Burst c. Damper d. Fly back30. The HV anode supply for a picture tube of a TV receiver is generated in thea. Mains transformerb. Vertical output stagec. Horizontal output staged. Horizontal oscillator31. The output of vertical amplifier isa. Direct currentb. Amplified vertical sync pulsec. A saw tooth voltage
  38. 38. d. A saw tooth current32. In a transistor if Alpha = 0.98, current gain is equal toa. 29 b. 59 c. 69 d. 4933. The active region in the common emitter configuration meansa. Both collector and emitter junction is reverse biasedb. The collector junction is forward biased and emitter junctionc. The collector junction is reverse biased and emitter junction is forwared biasedd. Both collector & emitter junction are forward biased34. The saturation region in the common emitter configuration means that
  39. 39. a. Both collector & emitter junction are reverse biasedb. The collector junction is forward biased and emitter junctionc. The collector junction is reverse biased and emitter junction is forwared biasedd. Both collector & emitter junction are forward biased35. The % of Red, Green & Blue in 100% White Y is given bya. 30%, 59%, 11%b. 50%, 30%, 11%c. 30%, 11%, 50%d. 33.3%, 33.5%, 38.3%36. Equalizing pulse width, if H is the Horizontal sync ratea. 0.64 H b. 0.07 H c. 0.04 H d. 0.16 H
  40. 40. 37. In a simple RC network the bandwidth is equal toa. 1/2 p RCb. RC / 2c. 2 C / p Rd. 2 p / RC38. The time constant of a RC network is given bya. RC b. C/R c. R/C d. None of these39. First zero crossing of pulse frequency spectrum occurs at if d is the pulse width, T is the pulserepetition ratea. 1/d b. d/T c. T/d d. T
  41. 41. 40. The distortion less output characteristic of a network meansa. Constant amplitude and linear phase shift over frequencyb. Linear phase shift and amplitude need not be constantc. Any amplitude and phased. None of these41. Single sideband means suppresseda. Carrierb. Carrier and one side bandc. One side bandd. None of these
  42. 42. 42. In an amplitude modulated signal, lower side band frequency is equal to (if the carrier frequency is fcand modulation frequency is fm)a. fm + fc b. fc – fm c. fm r fc d. fc / fm43. Modulation index of the frequency modulation depends ona. Amplitude & frequency of the modulation signalb. Frequency and amplitude of carrier signalc. Carrier frequencyd. None of these44. The BW of the narrow band FM if modulating frequency is fma. 3 r fm b. 2 r fm c. 2.5 r fm d. 10 r fm
  43. 43. 45. Reactance tube modulator is known fora. FM b. AM c. PPM d. PAM46. Bandwidth and rise time product isa. 0.35 b. 0.45 c. 0.30 d. 0.4947. Energy gap, Lg, for Germanium at room temp [300o K] isa. 0.72eV b. 1.1eV c. 1.53eV d. 0.2eV48. Volt equivalent of temperature VT, at 116o K isa. 0.11V b. 0.01V c. 1.16V d. 0.1V49. Reverse saturation current of a Ge.diode is in the range of
  44. 44. a. mA b. uA c. nA d. pA50. Cut-in voltage V for silicon is approximatelya. 0.2V b. 0.6V c. 0.9V d. 1.1VAnswersb21. a22. c23. c24. a25. b26. b27. c28. d29. b30. c31. d32. d33. c34. d35. a36. c37. a38. d39. a40. a41.b42. b43. a44. b45. b46. a47. a48. b49. b50.51. Every 10o C rise in temp. the reverse saturation currenta. Doublesb. Halvesc. Triplesd. No change
  45. 45. 52. Hall effect with reference to Metal or Semiconductor carrying a current I is placed in atransversemagnetic field B, an electric field E is induced ina. Parallel to Bb. Perpendicular to Ic. Perpendicular to both B & Id. Perpendicular to B53. 1 eV (electron volt) is equal to:a. 1.9 r 10-20 Jb. 1.6 r 10-19 Jc. 1.6 r 10-20 Jd. 1.16 r 10-19 J54. Donar impurity is having a valency of:
  46. 46. a. 2 b. 3 c. 4 d. 555. Acceptor impurity is having a valency ofa. 2 b. 3 c. 4 d. 556. Electron volt arises from the fact that if any electron falls through a potential of 1 volt, its kineticenergy willa. Decrease, & potential energy will increaseb. Increase & potential energy decreasec. Be unaltered & potential energy decreasesd. Increase & potential energy increase57. Hole is created in a semiconductor material if one of following impurities are added
  47. 47. a. Antimonyb. Arsenicc. Indiumd. Phosphorus58. Excess electron is created bya. Boranb. Galliumc. Indiumd. Arsenic59. A snubber circuit is used across the SCR to protect againsta. The di/dt of the anode current
  48. 48. b. The dv/dt turn onc. L.di/dt of load inductanced. None of these60. Germanium has the valency ofa. 2 b. 3 c. 4 d. 561. Silicon has the valency ofa. 2 b. 3 c. 4 d. 562. Hole acts as a free charge carrier of polaritya. Negative
  49. 49. b. Positivec. Neutrald. None of these63. Burst signal in NTSC system is 8 cycles of the frequency ofa. Colour sub carrierb. Picture carrierc. Sound carrierd. None of these64. Colour sub carrier reference burst is superimposed on thea. Back porch of the each horizontal sync pulseb. Front porch of the each horizontal sync pulse
  50. 50. c. Front porch of the each vertical sync pulsed. Back porch of the each vertical sync pulse65. The law of mass action with reference to semiconductor technology states that the product of freenegative & positive concentration is a constant anda. Independent of amount of donor and acceptor dopingb. Dependent on amount of donor and independent of the amount acceptor impurity dopingc. Depend on amount of both donor & acceptor impurity dopingd. None of these66. The snubber circuit used across SCR is a simplea. R-L networkb. RLC network
  51. 51. c. LC networkd. RC network67. To limit the rate of rise of SCR anode current a smalla. Inductor is inserted in cathode circuitb. Inductor is inserted in anode circuitc. Capacitor is inserted in anode circuitd. Capacitor is inserted in cathode circuit68. Torque developed by a DC servo motor is proportional to thea. Product of power and timeb. Product of armature current and back emfc. Armature voltage and armature current
  52. 52. d. Field voltage and field current69. Proportional Integral controla. Reduces steady state error but reduces the forward gainb. Increases the forward gain and reduces the steady state errorc. Increases the steady state error and increases the forward gaind. None of these70. Increasing the servo bandwidth:a. Improves signal to noise ratiob. Improves speed response and lowers signal to noise ratio
  53. 53. c. Improves power outputd. None of theseAnswersb51. a52. c53. b54. b55. b56. b57. c58. d59. b60. c61. c62. b63. a64. a65. a66. d67. b68. b69. a70. b71. Notch filter isa. Low pass filterb. High pass filterc. Narrow stop band filterd. Narrow pass band filter72. In TV Receivers the Electron beam deflection method used isa. Electro staticb. Electro magnetic
  54. 54. c. Magneticd. All the above73. In a line of sight communication the maximum range R in miles between the receiver antenna andtransmitter antenna of height H in feet is approximatelya. R = 1.93 ÖHb. R = 1.23 ÖHc. R = 1.53 ÖHd. R = 2.03 ÖH74. In wavelength of the 60 MHz carrier frequency isa. 10 metresb. 15 metres
  55. 55. c. 5 metresd. 2.5 metres75. In standard TV receiving antenna the dipole element isa. 0.5 of the wave lengthb. 0.25 of the wave lengthc. 1.5 of the wave lengthd. 1.0 of the wave length76. The characteristics of FET are similar to:a. Triodeb. Tertodec. Pentode
  56. 56. d. Diode77. Charge coupled device is an array of capacitors whose structure is similar to:a. Shift registerb. Flip-flopc. NAND gated. Amplifier78. Operational amplifier characteristics are which of the following:a. Infinite gainb. Infinite input impedancec. Output impedance is zero
  57. 57. d. All of the above79. The typical value of the open loop gain in dB of an amplifier at DC with no feedback is:a. 90 to 100b. 80 to 90c. 0 to 50d. 50 to 7080. The 3 dB band width means the frequency at whicha. The open loop voltage gain reduced to 0.707b. The open loop gain reduced to unityc. Maximum voltage of a signal is without distortiond. It is a medium wave band width of radio receiver
  58. 58. 81. Rise time of an amplifier is defined as time requireda. To change from 0 to 100 % of its final valueb. To change from 0 to 50 % of its final valuec. To change from 10 to 90 % of its final valued. To change from 10 to 100 % of its final value82. High speed amplifier design emphasized ona. Extremely small bandwidthb. Very slow responsec. Unity gain bandwidth after 10 MHzd. None of these
  59. 59. 83. Tuned amplifier having the frequency range betweena. 150 KHz – 50 MHzb. 100 Hz – 100 KHzc. 100 KHz – 120 KHzd. 50 MHz – 100 MHz84. The resonance frequency of a tuned circuit made up of R, L, C is given bya. 1/2 pÖLCb. 2 pÖLCc. 2 p / ÖLCd. ÖLC / 2
  60. 60. 85. The voltage follower can be obtained using operational amplifiera. Without any feedbackb. Series parallel feedback of unityc. Parallel feedbackd. Series feedback86. Fidelity of the amplifier is whena. It is a linear amplifierb. It does not add or subtract any spectral componentsc. It amplifier each component by the same amountd. All of the above
  61. 61. 87. What would be the output when two input sine waves of frequency 50 KHz and 100 KHz passedthrough an amplifier in the medium signala. 50 KHz and 100 KHzb. 100 KHz and 200 KHzc. 50 KHz and 150 KHzd. All of the above88. The important application of Schmitt trigger isa. To convert slowly varying input voltage to abrupt voltage changeb. To convert abruptly varying input voltage into slowly varying outputc. To change the frequency of the inputd. None of these89. Meaning of decoding is
  62. 62. a. Binary additionb. Data transmissionc. Demultiplexingd. Storage of binary information90. Approximately how many number of gates are incorporated in SSL chipa. 12b. 100c. Excess of 100d. Excess of 100091. The circuit diagram represents which one of the following
  63. 63. a. Half adderb. Full adderc. Exor gated. AND gate92. Flip flop cannot be called asa. Bistable multivibratorb. 1 Bit memory unitc. latchd. combinational circuit93. The important use of low pass filter in power supply isa. To get the regulation in the output voltage
  64. 64. b. To filter out the ripple frequencyc. To increase the current ratingd. To convert AC into DC94. Binary equivalent of the decimal number 145 isa. 10010001b. 1001011c. 1010001d. 110001095. In which of the following gate the output will be high when all the maintained at high levela. NOR
  65. 65. b. ANDc. NANDd. EXOR96. Which of the following definition is true in the De Morgan’s theorema. Multiplication symbols are replaced by addition symbolb. Addition symbols are replaced by Multiplication symbolc. Each of the terms are expressed in the complementary formd. All of the above97. 8421/BCD code fro a decimal number 149 isa. 0001 0100 1001b. 10010101
  66. 66. c. 10101001d. None of these98. Combinational circuit are mainly characterized bya. Output depends upon the previous state & presents stateb. Output depends upon the input at that particular instantc. Output depends upon the presents state & the clock stated. Output does not depends upon the input at all99. A flip flop is defined asa. A bistable device with two complementary outputsb. It is memory element
  67. 67. c. It will respond to input and it is a basic memory elementd. All of the above100. Four bit code is calleda. Nibbleb. Bytec. Wordd. RegisterAnswer:-.71. c72. c73. b74. c75. a76. c77. a78. d79. d80. a81. c82. c83. a84. a85. b86. d87. a88. a89. c90. a91. a92. d93. b94. a5. b96. d97. a98. b9. d100.a
  68. 68. 1. The gray code equivalent of binary 1100 isa. 1011 b. 1101 c. 1010-and d. 11002. A Multiplexer hasa. Multiple inputs and single outputb. Single input and Multiple outputsc. Multiple inputs and Multiple outputs-ansd. Multiple inputs for Storage of Data3. A binary half adder
  69. 69. a. Adds two binary digits and produces their sum and carry-ansb. Adds half the sum to the carryc. Adds two binary digits and carry from previous additiond. Adds two binary digits at half the speed4. An index register in a computer is fora. Arithmetic and logic functionsb. Storage of resultsc. Modifying the address-ansd. Counting the no of programmes5. An example of volatile memory is
  70. 70. a. RAM-ans b. ROM c. EPROM d. Magnetic tape6. Barrier voltage in a P-N junction is caused bya. Thermally generated electrons and holesb. Diffusion of majority carriers across the junction-ansc. Migration of minority carriers across the junctiond. Flow of drift current7. The temperature coefficient of an intrinsic semiconductor isa. Positive b. Negative-ans c. Zero d. Like metals8. A silicon transistor has a leakage current 1cbo = 1 ma. If the temp. rises by 50o C the leakage currentwill bea. 30 ma b. 32ma-ans c. 50ma d. no change
  71. 71. 9. The noise figure of an ideal amplifier in decibel isa. 0.5 b. 0-ans c. 1 d. 1010. The rise time of an amplifier is 200 nsec. Its bandwidth isa. 70MHz b. 140MHz c. 100MHz d. 1.75Mhz-ans11. MOSFET operates ina. Depletion mode onlyb. Enhancement mode onlyc. Depletion and enhancement mode-ansd. None of these of the above
  72. 72. 12. A device which behaves like SCRs isa. UJT b. Triac-ans c. MOSFET d. SRD13. A plate modulated class C RF amplifier produces 100 KW of radiated power at 100 % modulation.The modulating audio amplifier supplies approximatelya. 25KW b. 33KW-ans c. 50KW d. 66KW14. A 100 MHz FM carrier, modulated by a 5 KHz sine wave deviates by 50 KHz If the frequency of themodulating sine wave is doubled, the deviation willa. Double b. Half c. Quadruple d. Have no change-ans15. Noise generated by a resistor is dependent ona. Its Value
  73. 73. b. Its temperaturec. Both value and temp-ansd. None of these16. A 32 channel 8 bit PCM system samples at 8 KHz rate. The overall bit rate in kilobits per second willbea. 2048-ans b. 2000 c. 1920 d. 6417. Stub matching eliminates standing wave ona. Load side of the stubb. Source side of the stubc. Both sides-ansd. On the stub
  74. 74. 18. A half wave folded dipole has a radiation resistance ofa. 72 W b.50W c. 144W d. 288W-ans19. Top loading is used in antennas fora. Decrease in impedanceb. Increase in bandwidthc. Increase in effective height-ansd. Decease the height20. The term critical frequency in Ionospheric propagation isa. Lowest frequency reflected by Ionosphereb. Highest frequency reflected by the Ionosphere at vertical incidence-ans
  75. 75. c. Lowest frequency reflected by the Ionosphere at vertical incidenced. Lowest communication frequency possible21. The cathode ray oscilloscope can be used to measurea. Frequency b. Time interval c. Voltage d. All the above-as22. A wein bridge is used for measurement ofa. Resistance b. Capacitance c. Inductance d. Audio frequency-ans23. The frame rate per second used in India TV isa. 60 b. 50 c. 25-ans d. 3024. VHF signals are propagated
  76. 76. a. Via the ionosphereb. Along the ground-ansc. Through the troposphered. By reflection in ionosphere25. The impedance of a 3 element yagi antenna is arounda. 75W b. 300W-ans c. 50W d. 100W26. A PIN diode is microwavea. Oscillator b. Mixer c. Detector d. Switch-ans27. A transmission line of VSWR 2 has a reflection coefficient
  77. 77. a. 0.25 b. 0.5 c. 75-ans d. 028. Microwave repeaters are typicallya. 25 b. 50-ans c. 75 d. 100 Kms apart29. To overcome fading in a ship-to-ship communication system we can efficiently usea. Broadband Antennab. Directional Antennac. Space Diversityd. Frequency Diversity-ans30. Frequency in the UHF range is propagate by waves ofa. Ground b. sky c. Space-ans d. Surface
  78. 78. 31. A duplexer is used toa. Receive two signals in one antennab. Prevent interference between two antennac. Mix two signals to the same antennad. Allow one antenna for both transmission and reception-ans32. Strapping is used in a magnetron toa. Prevent mode jumping-ansb. Reduce frequency driftc. Ensure proper bunchingd. Dissipate heat
  79. 79. 33. A rectangular waveguide behaves like a filter ofa. Band pass b. High pass-ans c. Low pass d. Band stop34. The signal propagation time in milliseconds for a geosynchronous satellite isa. 540 b. 270 c. 135-ans d. 10035. The silicon solar cell is aa. Photo conductiveb. Photo emissivec. Photo voltaic-ansd. Photo resistive
  80. 80. 36. For the national TV and ratio network, INSAT-IB usesa. 400MHz b. 2.5GHz c. 2.5 and 5GHz d. 4 and 6 GHz-ans37. A typical fibre-optic detector isa. Step recovery diodeb. Light emitting diodec. Avalanche photo diode-ansd. Field effect transistor38. A modem is a device used fora. Digitizing voice datab. Transmission of data on lines
  81. 81. c. Modulating and demodulating signals sent on a line-ansd. Suppressing noise interference39. The most effective anti-jamming technique isa. Frequency hopping-ansb. Spread Spectrumc. Frequency synthesisd. Burst transmission40. Mono-mode is a term used ina. Fibre-optics-ansb. Radarc. Satellite communication
  82. 82. d. Magnetics41. Monopulse technique is used ina. Radar-ansb. Radio relayc. Data communicationd. Fibre-optics42. HDLC is a term fora. Data communication protocol-ansb. Synchronizing pulsesc. Gain control in receivers
  83. 83. d. Error checking43. A gatewaya. Is a place where radars are connectedb. Permits dissimilar networks to communicate-ansc. Bifurcates the RF path of a transmitterd. Is a feeder cable44. Ethernet is a name ofa. Medium of computer communicationb. Network for computer communication-ansc. Procedures for computer communication networkd. Software for computer communication
  84. 84. 45. If several stations in a network want to use a single channel without interfering with one another,the technique used is calleda. Carrier senseb. Phantom-freezec. Packet switchingd. Multiplexing-ans46. In a monolithic IC, resistors are formed froma. Ceramic materialsb. Copperc. P-type semiconductor-ans
  85. 85. d. Aluminium deposition47. ICs made by sputtering of materials on a ceramic substrate are calleda. Monolithic b. Hybrid c. Thick film d. Thin film-ans48. Two coils (inductors) connected in series have a combined inductance of 15mH. When terminals ofone of the coils are reversed and connected to the other, the combined inductance is measured to be9mH. What is the value of mutual inductancea. 1.5mH b.3mH c.6mH d.12mH49. If a parallel LC circuit is excited at frequency less than its resonant frequency, the nature of itseffective impedance isa. Resistive b. Inductive c. Capacitive d. None of these of these50. The wave length of 1 Giga hertz frequency signal is
  86. 86. a. 10cm b. 30cm c. 3cm d. 1cm51. Which of the following microwave tubes can be considered as broad band devicesa. Magnetronsb. Klystronsc. Reflex klystronsd. Traveling wave tubes[TWT]52. Which family of the following integrated circuits has the highest speeda. DTL b. ECL c. TTL d.CMOS53. The most important feature of CMOS family of ICs isa. High speed
  87. 87. b. Small sizec. Low power consumptiond. Low input impedance54. What is the resolution of 8 bit A/D converter if its full scale voltage is 10va. 0.02v b. 0.01 c. 0.039v d. 0.078v55. What value of resistance is to be used in LSB of 4 bit weighted ladder D/A converter if MSB has 10kW resistora. 160k b. 80k c. 240k d. 100k56. The pulse width of a radar transmitter is 0.6m sec. and the pulse repetition rate is 700 Hz. Theaverage power measured is 420 watts. What is the peak powera. 100KW b. 420KW c. 1MW d. None of these
  88. 88. 57. The device used for isolating the transmitter and receiver in a radar system is calleda. Diplexerb. Duplexerc. Directional couplerd. None of these58. “Baud” isa. Total No. of bits/sec in each characterb. Reciprocal of shortest signal element in a characterc. Duration of a character in data transmissiond. None of these
  89. 89. 59. The advantage of Totem pole output stage in TTL ICs isa. Low output impedanceb. Can sink more currentc. Oscillations avoidedd. None of these60. The capacitance value of a varactor is controlled bya. A reverse voltage applied to itb. A series resistancec. Varying its supply voltaged. Current through the deviceAnswers
  90. 90. b50. b51. d52. b53. c54. c55. b56. c57. b58. b59. a60. a61. Electron volt is equivalent toa. 3.8 * 10-20 ergb. 1.602 * 10-12 ergc. 1.602 * 10-18 ergd. 1.602 * 10-16 erg62. The kinetic energy of photo electrons emitted by a photo sensitive surface depends ona. Intensity of the incident radiationb. Wavelength of the incident radiationc. Angle of incident of radiation
  91. 91. d. Surface conditions of the surface63. Flux is expressed in radio-metric system ina. Lumensb. Photonsc. Wattsd. Candles64. In a three-phase bridge rectifier circuit, the ripple frequency isa. Same as line frequencyb. Twice the line frequencyc. Thrice the line frequencyd. Six times the line frequency
  92. 92. 65. Energy stored in a capacitor as a function of voltage is given bya. CV2b. 1V2/2Cc. ½ CV2d. 1V/2C66. The operational amplifier used in analog computers have usually open loop flat gain approximatelyuptoa. 1MHz b. 100MHz c. 10MHz d. 0.1MHz67. An oscillator of 350 MHz is fed with a pulse of rise time 2 n sec. The rise time of the displayedwaveform is approximatelya. 1 n sec b. 2.2 n sec c. 2.0 n sec d. 1.7 n sec
  93. 93. 68. A radar transmits a peak power of 100 KW with pulse width of 1 m sec and a pulse repetition rate of100 KHz. The average output power of the radar isa. 100KW b.10KW c. 1000KW d. 50KW69. The incremental inductance in a coil is due toa. Saturationb. Superimposed DCc. Mutual inductanced. Change of frequency70. Microwave tube based on velocity modulation principle isa. Klystronb. Magnetron
  94. 94. c. Light house tubed. Traveling wave tubeAnswers61. b62. b63. a64. b65. c66. d67. c68. b69. d70. a71. a72. a73. b74. a75. b76. a77. b78. a79. a80. b71. Noise output from the receiver decreases uniformly with noise side band frequency fora. Frequency modulationb. Amplitude modulationc. Pulse amplitude modulationd. None of these72. In amplitude modulation the maximum permissible modulation index isa. Unity b. 100 c. infinity d. None of these
  95. 95. 73. In frequency modulation the maximum permissible modulation index isa. Unity b. 50 c.1000 d. no limit74. In FM transmission and reception, the pre-emphasis and de-emphasis are used to improve thea. Signal to noise ratiob. Frequency response of the receiverc. Frequency response of the transmitterd. The sensitivity of the transmitter75. De-emphasis network uses the combination ofa. R-L b. R-C c. R-L-C d. Transformer
  96. 96. 76. The usage of micro sec for defining emphasis is a standard practice but this micro sec definitionmeansa. 3 dB point of the network meansb. mid point of the network responsec. roll off the network responsed. the stop band ripple of the network response77. Delayed AGC is applieda. For all singal strengthb. For singal strength exceeding a specified limitc. For low singal strengthd. For FM receiver
  97. 97. 78. Selectivity meansa. Bandwidthb. Gainc. Modulation indexd. None of these79. Narrow bandwidth broadcast reducesa. The quality and noiseb. Quality alonec. Noise aloned. Quality and intelligibility
  98. 98. 80. Squelch means keeping the receivera. ON in the absence of carrierb. OFF in the absence of carrierc. To remove AGCd. Increase the AGC81. Let Z be the series impedance and Y be the shunt admittance of the transmission line, then thecharacteristic impedancea. ÖZY b.ÖY/Z c. ÖZ/Y d.All the above82. Noise figure of an amplifier is defined asa. Input SNR output SNRb. Input SNR / output SNRc. Output SNR / input SNRd. Input SNR / gain
  99. 99. 83. A broadcast radio transmitter radiates 10 KW power when modulation is 60%. Its carrier power willbea. 8.47KW b.8.92KW c. 8.31KW d.10.00KW84. In AM transmission antenna current is 8 Ampere at zero modulation indexes but increased to 8.93Ampere when modulated on single sine wave. Then the % of modulation is approximatelya. 70.1% b. 80.1% c. 65.1% d. 10.0%85. In AM transmission antenna current is 8 Ampere at zero modulation index. At 80% modulation indexthe antenna current will bea. 10.00A b. 8.72A c. 9.19A d. 9.79A86. If two sine waves are amplitude modulated with modulation index m1 and m2, the effectivemodulation index is
  100. 100. a. Ö m12/m22b. Ö m1 m2c. Ö m12+m22d. Ö m22/m1287. If it is transmitted current and Ic is transmitter current at zero modulation index and the transmittedcurrent at modulation index of m willa. It = Ic Ö[1+m]b. It = Ic Ö[1+m2]c. It = Ic Ö[1+m/22]d. It = IcÖ1+m288. If Rr is the radiation resistance and Rd is the lumped resistance, then the antenna efficiency is givenas –
  101. 101. a. (Rr - Rd) / (Rr + Rd)b. (Rr + Rd) / (Rr – Rd)c. Rr / (Rr + Rd)d. Rd / (Rr + Rd)89. In end fire array, the currenta. Magnitude and phase in each element is the sameb. Magnitude is the same but phase is different in each elementc. Magnitude is different but no phase difference in each elementd. Magnitude and phase are different in each element90. In a board side array, the current
  102. 102. a. Magnitude and phase in each element is the sameb. Magnitude is the same but phase is differentc. Magnitude is different but no phase difference in each elementd. Magnitude and phase are different in each element91. Beam width of the 2 metre paraboloid reflector at 6 GHz isa. 4.5ob. 9.25oc. 3.5od. 7.75o92. The cut of wave length for TE m, n mode is in a wave guide of dimension a*b isa. 2/Ö(m/a)2 +(n/b)2
  103. 103. b. 2Ö [m/a]2 + [n/b]2c. Ö(m/a)2 + (n/b)2 /2d. Ö [m/a]2 + [n/b]293. For the standard rectangular waveguide dimension of 4*2 cm the off wavelength for TM11 mode isapproximatelya. 1.788cm b. 3.576cm c. 1.682cm d. 2.546cm94. In IMPATT diode, the voltage and current area. In phaseb. Out off phase by 90oc. Out off phase by 180od. None of these of the above
  104. 104. 95. Which of the following statement is truea. Tunnel diode & IMPATT diode are negative resistance devicesb. Tunnel diode is positive resistance device and the IMPATT diode is negative resistance devicec. Tunnel diode is negative resistance device and the IMPATT diode is positive resistance deviced. None of these of the above96. In a SSB modulation system with 100% modulation index the power saving will bea. 5/6 of carrier powerb. 2/8 of carrier powerc. 5/12 of the carrier powerd. ½ of the carrier power
  105. 105. 97. In SSB modulation the modulation index is increased from 0.5 to 1.0, then the power will beincreased bya. 2 times b. 4 times c. 16 times d. 32 times98. 900 rpm is equal toa. 94.2 rad/secb. 47.1 rad/secc. 188.4 rad/secd. 16.72 rad/sec99. Darlington pair is used toa. Increase the voltage gainb. Increase the current gain
  106. 106. c. Decrease voltage gaind. Decrease current gain100. The transfer function of the system shown isa. G(s) / {1 + H(s)}b. G(s) H(s) / {1 + G(s) H(s)}c. G(s) / {1 + G(s) H(s)} d. G(s) / G(s) H(s)-ansAnswers81. c82. b83. a84. a85. c86. c87. c88. c89. b90. a91. c92. a93. b94. c95. a96. a97. b98. b99. b100. c2011 BEL Placement Paper:-
  107. 107. 1. In which of the following movements ‘Vande Mataram’ was adotped for the first time as a slogan foragitation?(A) Revolt of 1857(B) Partition of Bengal in 1905(C) Non-cooperation Movement in 1922(D) Quit India Movement in 19422. Who warned Gandhiji not to encourage fanaticism of Muslim religious leaders and their followers?(A) Agha Khan(B) AjmaI Khan(C) Hasan Imam
  108. 108. (D) Mohammad Ali Jinnah3. Which one of the following is not correct about the Congress Session.of Lucknow, 1916?(A) Ambika Charan Majumdar was not the president of this session(B) In this session the reunion between the liberal and the extremist was established(C) Mahatma was apprised the problems of the peasants Champaran for the first time(D) None of the above4. Kanpur conspiracy case was against the leaders of?(A) Khilafat Movement
  109. 109. (B) Non-cooperation Movement(C) Communist Movement(D) Revolutionary Movement5. In India “Currency Notes issue system” is based on?(A) Minimum reserve system(B) Proportional reserve system(C) Fixed exchange rate system(D) Full convertibility system6. ‘Disguised’ unemployment means?
  110. 110. (A) Persons with no jobs(B) Unemployment among house wives(C) Unemployment among per sons above 60 years pf age(D) Employment of more persons in a job which lesser number of persons can perform7. Which of the following statements are true about the income tax in India?1. It is a progressive tax,2. It is a direct tax.3. It is collected by the Government.4. It is a proportional tax Select the correct answer from the code given below
  111. 111. Codes:(A) 1 only(B) 1 and 2 only(C) 1,2and3only(D) 2, 3 and 4 only8. ‘SIDBI’ has been established to-(A) Finance small scale industries(B) Finance cottage industries(C) Finance large scale industries(D) Finance public sector under takings
  112. 112. 9. Gangubai Hangal, who died a few months ago, was a?(A) Classical singer(B) Dancer(C) Painter(D) Sitar player10. Deep Joshi has recently been given Raman Magsaysay Award in the category of?(A) Government service(B) Public service(C) Community leadership
  113. 113. (D) Emergent leadership11. The missing number in the following series: 5,10,13,26,29, 58, 61,…Is?(A) 122(C) 128(B) 125(D) 13112. If 2 jeans and 3 shirts cost Rs. 4,000 and jeans and 2 shirts cost Rs. 3,500, how much does a jeanscost?(A) Rs. 1,500(B) Rs 1,000
  114. 114. (C) Rs. 500(D) Rs. 2,00013. Which one of the following expresses error in computer data?(A) chip(B) byte(C) bug(D) bit14.Assertion (A) Graphite is a good lubricant. Reason (R) Graphite is good conductor of electricity. Selectthe correct answer from the codes given below Codes:
  115. 115. (A) Both (A) and (R) are true and (A) is the correct explanation of (A)(B) Both (A) and (A) are true but (H) is not the correct explanation of (A)(C) (A) is true but (R) is false(D) (A) is false but (A) is true15. Acid rain is caused by pollution ot environment by?(A) Carbon dioxide and Nitrogen(B) Carbon monoxide and Carbon dioxide(C) Ozone and Carbon dioxide(D) Nitrous oxide and Sulphur dioxide
  116. 116. 16. The professional printed circuit board generally use the following as the raw material:1.Paper base bakelite copper clad sheet2. Glass epoxy copper clad sheet3.Tin plated Nylon sheet4. Silver plated pyrex sheet17. Many switch contacts use silver as the material because1. It is a good electrical conductor with low contact resistance2. Silver does not tarnish3. It is easily shaped as per requirement
  117. 117. 4. It is very hard and does not wear off18. A resistance of approximate value 85W is to be measured by using an ammeter of range 0-1 A havinga resistance of 20 W and voltmeter of range 0-50V having a resistance of 5000W. Two arrangement forthe measurement are shown in the figure below. Which method would you recommend?1. Method X2. Method Y3. Either X or Y4. Neither X nor Y19. The value of capacitance across points A & B in the circuit shown below is (in microfarads)
  118. 118. a. .3 b. 1 c. 0.67 d. 0.3320. It is proposed to fabricate a simple Ohm meter for measuring resistor values. A milliammeter withan internal resistance of 50 W is available. Choosing a configuration using a 3 V battery, a largeresistance and the ammeter in a loop, the unknown resistor is proposed to be measured by noting thecurrent initially and then connecting the unknown resistor across the ammeter. If the ratio of the twocurrent is 2, what is the value of the unknown resistor (rn W ) ?a. 3000 b. 150 c. 100 d. 5021.The current I flowing into the branch indicated by an arrow in the circuit shown is equal toa. 2 Amp b. 0.5 Amp c. 1 Amp d. 0.25 Amp
  119. 119. 22. For the circuit shown, the maximum power is delivered to the load resistance RL when the value ofRg isa. 2 ohms b. zero c. 10 ohms d. infinity23. A signal generator is available in the laboratory, which is in good condition except for the attenuatordial which has got displaced. In order to calibrate this, a high frequency oscilloscope is available. At aparticular setting of the knob an open circuit voltage of 450 mV rms is measured. If the impedance ofthe generator is 50 ohms, the setting of the attenuator dial is to be adjusted fora. 6 dBm b. 1 dBm c. 0 dBm d. 10 dBm24. The relation Loge (X + Loge (1 + X) = 0 also means that1. X2 + X + 1 = 0
  120. 120. 2. X2 + X - 1 = 03. X2 + X + e = 04. X2 + X – e = 025. The Laplace transform of the function f(t) = cos wt is1. w/(s2 + w2)2. s2/(s2 - w2)
  121. 121. 3. w2/(s2 + w2)4. s/(s2 + w2)26. If a = b = c, one value of X which satisfies the equation=0 is given bya. x=a b. x=b c. x=c d. x=027. An LC oscillator is being analysed. If the LC tank circuit (with quality factor = Q) is isolated from theamplifying device, the impedance at the resonant frequency as measured looking into the amplifier willbe
  122. 122. 1. Q r [LC]1/22. ½ rp r [LC]1/23. – Q r[LC]1/24. Q r [LC]1/228. A battery eliminator is required to be constructed and an assortment of rectifiers, resistors andcapacitors is available. However, the step down transformer available has no center tap. The followingconfigurations for the rectifier are feasible. The one giving the lowest ripple will be1. Full wave rectifier
  123. 123. 2. Half wave rectified3. Bridge rectifier4. None29. Chokes used in rectifier filter circuits are wound on a core with a small air gap. This is done in orderto1. Get as high an inductance as possible2. Prevent saturation of the core3. Absorb the ripple effectively4. Prevent loading the transformer30. An integrated circuit linear regulator is used at the output of a power supply having a ripple of 1 Vrms. Assuming that the IC represents a typical design generally available, the output rms ripple to beexpected will be
  124. 124. a.. 0.1 V rms b. 0.1 mV c. 100 mV d. 1.0 V rms Here are the details of 2011 BEL Placement Paper - II job in Bharat Electronics Limited - BEL1. Which one of the following is called the ‘metal of future’?(A) Copper(B) Iron(C) Titanium(D) Aluminum
  125. 125. 2. The earliest coins of India were made of ?(A) Copper(B) Gold(C) Lead(D) Silver3. The Mongols appeared for the first time on the banks of Indus during the reign of?(A) Balban(B) Iltutrnish(C) Qutubuddin Aibak
  126. 126. (D) Razia4. The first woman ruler of medieval India was?(A) Chand Bibi(B) Durgavati(C) Noorjahan(D) Razia5. The Moplah Rebellion (1921) took place in?(A) Malabar
  127. 127. (B) Marathawada(C) Telengana(D) Vidarbha6. Which part of the Constitutions of India has been described as the: Soul of the Constitution ?(A) Directive principles of State policy(B) Fundamental rights(C) Preamble(D) Right to constitutional remedies7. The first state to implement the Panchayati Raj System in India was?
  128. 128. (A) Uttar Pradesh(B) Rajasthan(C) Gujarat(D) Karnataka8. Who has the right to seek advisory opinion of the Supreme Court on any question of law?(A) Prime Minister(B) President(C) Any High Court(D) All of the above
  129. 129. 9. Consider the following statements about the Governor of a State1. He is appointed by the President.2. He holds office at the pleasure of the President.3. The executive power of the: State vests in him.4. Normally he holds office for five years.Select the correct answer from the codes given below(A) l and 2(B) 1,2 and 3(C) 1,2 and 4(D) All the four10. Which one of the following pairs is not correctly matched ?
  130. 130. (A) Ahmedabad—Sabarmati(B) Lucknow —Gomti(C) Bhubaneshwar—Mahanadi(D) Ujjain-Shipra11. Dilwara Jain temple is situated at?(A) Palitana(B) Mount Abu(C) Sonagiri(D) Girinarji
  131. 131. 12. Which one of the following is the biggest shipping canal in the world?(A) Kiel Canal(B) Panama Canal(C) Soo Canal(D) Suez Canal13. Where was the battle of Plassey fought?(A) Karnal(B) Haldighati(C) Mysore
  132. 132. (D) Bengal14. Who was the first Vice-President of India?(A) Dr. S. Radhakrishnan(B) Dr. Rajendra Prasad(C) C. V. Raman(D) Jawahar Lal Nehru15. What was the reason behind the mutiny of 1857?(A) Cartridge containing fat
  133. 133. (B) Frustration in soldiers(C) Failure of British Government(D) Administrative research16. For VHF interfering waves generated by automobile ignition systems or other electrical equipmentlocated close to the ground, specify which of the following components of the interfering signal aresignificant at receiving locations such as used in the reception of TV signals:1.Horizontal polarization component2.Vertical polarization component3. Both horizontal and vertical polarization components4. Neither horizontal nor vertical polarization components17. The ratio of lower frequency limit to the MUF for radio communication at short-wave is generally
  134. 134. 1. Smaller at night than in the day time2. Larger at night than in the day time3. Same at night and in the day time4. A maximum during the evening times18. Two UHF amateur radio antenna placed at the same height and 30 statute miles apart are to be suchthat each is on the radio horizon line of the other. The height of the antennas should bea. 56.25 ft b. 112.5ft c. 150ft d. 225ft19. A transmitter with a radiated power of 1 KW produces a field strengthof 300 mv/m at a distance of 1Km from the antenna. If the transmitter power is increased to 50 KW and the vertical directivity of theantenna is increased by a factor of 1.41, the field strength a the same distance from the antenna isapproximately
  135. 135. a. 1.5 V/m b. 2.115 V/m c. 3.0 V/m d. 6.0 V/m20. The directive gains of non-resonant and resonant wire antennas of equal length are approximately inthe ratio ofa.. 4:1 b. 1.5:1 c. 1:1 d 3:121.A simple wire radiator produces a radiation field of intensity 100 mV/m at a distance point 25 Kmaway. The field produced (in mV/m) at a point 50 Km away in the same direction isa. 25 b.50 c. 12.5 d. 10022. Assuming the plane of polarization of the incoming wave and the plane of the receiving antenna tobe the same, the effective height of the receiving antenna is proportional to
  136. 136. 1. Radiation resistance2. Power gain of the antenna3. Physical area of the antenna4. Wavelength, assuming other parameters being same23. The function performed by the following circuits is1. General combinational logic2. Exclusive OR logic3. Exclusive NOR logic4. Digital comparator logic
  137. 137. 24. Narrow trigger pulses are required to be generated from a square wave pluse train (pulse width =T). The linear wave shaping circuit would be an RC circuit (time constant = T) with the following features:1. High pass with T << T2. High pass with T >> T3. Low pass with T >> T4. Low pass with T << T25. The circuit given below acts as1. An OR gate2. An AND gate3. An inverter4. A NOR gate
  138. 138. 26. In the circuit shown below. if R = 0 and S = 1, the outputs Q and Q will be1. Q low, Q high2. Both low3. Q high, Q low4. Both high27. Schmitt trigger buffers are normally used as input buffers to digital logic circuit to achieve1. Higher isolation2. Higher fan-in-capability
  139. 139. 3. Higher drive capability4. Higher noise-immunity28. For a reverse-biased PN junction. If the applied voltage is doubled the junction capacitancedecreases by a factor of 2 ½. Assuming the junction acts as a parallel plate condenser, the averagespacing between the plates changes by a factor of1. 22 b.2 c. 1/21/2 d. 21/229. Many frequency sources use a piezo-electric resonator in the feedback circuit essentially to achievea1. Miniature product2. Low cost design3. Stable frequency
  140. 140. 4. Large output power30. A pulse train has the following characteristics:Peak amplitude = 10 V, Pulse ON time 1 secPulse OFF time = 4 secThe pulse train is passed through a high pass RC filter with a large time constant. The amplitude ofthe positive peak at the output will be1. .10 V b. 2V c. 4V d. 8V
  141. 141. TECHNICAL (100M)ENG +APTI+REASONING (100M)1.Ghost interference in TV is Due to?2. which of the following frequency is not used in TV Broad cast ?3. % of R,G,B in TV ?4.one problem on self bias circuit?5.four question on logic gate ?6. hexadecimal to decimal conversion?7.maximum &minimum voltages in TTL circuit ?8. fanout of TTL circuit ?9.if VSWR is 1, then |L|=?
  142. 142. 10.for maximum power transfer theorem |ZL|=?11.one question on capacitor filter, rectifier circuit ?12. three questions on fourier transform ?13. maximum efficiency achieved in class-A transformer fed power amplifier14. one question on polar plot ?15.one question on bode plot?16. four questions on measurements ?17.In DSB-SC ,demodulation quadrature null effect occurs when θ=?18.which of the following is generation of SSB-SC ..........19.formula for power of FM modulated signal ........20.n-type semiconductor formed due to si is doped with arsenic21. 1 byte is equal to 8-bits
  143. 143. 22. group of 4-bits used in nibble23. number of address lines required for 4096x12 ROM..........24.volatile memory .......... a) SRAM b)DRAM c)ROM25.Tachometer is used to measure SPEED26. the value of K for CLTF ,unconditionally stable T.F=ks/(s+1)(s2+s+1)27.determine the centroid for above CLTF?28.determine the angle of asymptotes ?29.Hays bridge is used when Q is ? a) Q<10 b)Q>10 c) 1<Q<1030. formula for skin depth is ?
  144. 144. . Transition capacitance Ct of a Varicap diode with Knee voltage Vt, reverse voltage Vr and K, theconstant based on semiconductor material and the construction technique & N dependent on type ofjunction is given bya. 1 / K (Vt + Vr)N/2b. 1 / K (Vt + Vr)Nc. K / (Vt + Vr)Nd. K / (Vt + Vr)1/N Answer : c2. Ct = K / (Vt + Vr)N where Vt Knee voltage, Vr reverse voltage, K manufacturing dependent constantand N dependent on type of junction, for alloy junction the value of N isa. 1/3b. 2/3
  145. 145. c. 1/2d. 1/4 Answer : c3. The distortion less output characteristic of a network meansa. Constant amplitude and linear phase shift over frequencyb. Linear phase shift and amplitude need not be constantc. Any amplitude and phased. None of these Answer : a4. Single sideband means suppresseda. Carrierb. Carrier and one side band
  146. 146. c. One side bandd. None of these Answer : b5. In an amplitude modulated signal, lower side band frequency is equal to (if the carrier frequency is fcand modulation frequency is fm)a. fm + fcb. fc – fmc. fm r fcd. fc / fm Answer : b6. The noise figure of a receiver is a measure of:
  147. 147. 1. Excess noise generated2. Bandwidth of the receiver3. Gain of the receiver4. Operating frequencyAnswer :17. The ratio receiver is:1. Direct detection type2. Super regenerative type3. Super heterodyne type4. None of theseAnswer : 3
  148. 148. 8. In an amplitude modulation system, the modulation index is dependent upon:1. Modulating frequency only2. Carrier amplitude only3. Modulating signal amplitude only4. Modulating and carrier amplitudes onlyAnswer : 29. Image rejection mixer is generally used:1. To reject the unwanted signal2. To improve signal amplitude3. To improve noise figure4. To improve conversion loss
  149. 149. Answer : 310. The value of a resistor creating thermal noise is doubled. The noise power generated is therefore:1. Halved2. Quadrapuled3. Doubled4. UnchangedAnswer : 211. Ct = K / (Vt + Vr)N where Vt Knee voltage, Vr reverse voltage, K manufacturing dependent constantand N dependent on type of junction, for diffused junction the value of N isa. 1/3b. 2/3c. 1/2d. 1/4
  150. 150. Answer : a12. In JFET, the drain current Id is given by (Idss drain – source saturation current Vgs – Gate – sourcevoltage, Vp the pinch off voltage)a. Idss[1 – Vp/Vgs]b. Idss(1 – Vgs/Vp)2c. Idss[1 – Vgs/Vp)d. Idss(1 – Vgs/Vp)3/2Answer : b13. The shadow mask in colour tube is used toa. Reduce X-Ray emissionb. Ensure each beam hits its own dots
  151. 151. c. Increase screen brightnessd. Provide degaussing for the screenAnswer : b14. Indicate which of the following signal is not transmitted in colour TVa. Yb. Qc. Rd. IAnswer : c15. Another name for horizontal retrace in TV receiver is thea. Ringing
  152. 152. b. Burstc. Damperd. Fly backAnswer : d16. Another name for the colour sync in the colour TV systema. Ringingb. Burstc. Damperd. Fly back Answer : b
  153. 153. 17. The HV anode supply for a picture tube of a TV receiver is generated in thea. Mains transformerb. Vertical output stagec. Horizontal output staged. Horizontal oscillatorAnswer : c18. The output of vertical amplifier isa. Direct currentb. Amplified vertical sync pulsec. A saw tooth voltaged. A saw tooth currentAnswer : d
  154. 154. 19. In a transistor if Alpha = 0.98, current gain is equal toa. 29b. 59c. 69d. 49Answer : d20. The active region in the common emitter configuration meansa. Both collector and emitter junction is reverse biasedb. The collector junction is forward biased and emitter junctionc. The collector junction is reverse biased and emitter junction is forwared biased
  155. 155. d. Both collector & emitter junction are forward biasedAnswer : c21. The saturation region in the common emitter configuration means thata. Both collector & emitter junction are reverse biasedb. The collector junction is forward biased and emitter junctionc. The collector junction is reverse biased and emitter junction is forwared biasedd. Both collector & emitter junction are forward biasedAnswer : d22. The % of Red, Green & Blue in 100% White Y is given bya. 30%, 59%, 11%b. 50%, 30%, 11%
  156. 156. c. 30%, 11%, 50%d. 33.3%, 33.5%, 38.3%Answer : a23. Equalizing pulse width, if H is the Horizontal sync ratea. 0.64 Hb. 0.07 Hc. 0.04 Hd. 0.16 HAnswer : c24. In a simple RC network the bandwidth is equal to
  157. 157. a. 1/2 p RCb. RC / 2c. 2 C / p Rd. 2 p / RCAnswer : a25. The time constant of a RC network is given bya. RCb. C/Rc. R/Cd. None of theseAnswer : d
  158. 158. 26. First zero crossing of pulse frequency spectrum occurs at if d is the pulse width, T is the pulserepetition ratea. 1/db. d/Tc. T/dd. TAnswer : a27. Indicated the false statement:1. HF mixer are generally noisier than HF amplifier2. Impulse noise voltage is independent of bandwidth3. Thermal noise is independent of the frequency at which it is measured4. Industrial noise is usually of the impulse type
  159. 159. Answer : 228. If the carrier of a 100 percent modulated AM wave is suppressed the percentage power saving willbe:a. 50b. 70c. 100d. 66.6 Answer : d29. A balanced modulator produces:1. The carrier and Two side bands2. The carrier and one side band3. Two side bands alone
  160. 160. 4. Carrier and a number of side bandsAnswer : 330. The frequency deviation in FM system is proportional to:1. Modulating frequency2. Carrier amplitude3. Modulating signal amplitude4. None of theseAnswer : 331. In FM, the total transmitted power is:1. Dependent on modulating signal amplitude
  161. 161. 2. Dependent on modulating frequency3. Dependent on modulating index4. Independent of the aboveAnswer : 432. A quarter wave line when short circuited at the far end behaves like1. Pure inductor2. Pure capacitor3. Parallel tuned circuit4. Series tuned circuitAnswer : 333. The stub line used to match transmission line with a given load impedance is generally
  162. 162. 1. Another open circuited line2. Another short circuited line3. Quarter wave transmission line4. Half wave transmission lineAnswer : 234. The smith chart generally covers a distance of1. Quarter wavelength2. Half wavelength3. One wavelength4. Twice the wavelengthAnswer : 2
  163. 163. 35. The component generally used to sample a portion of the energy transmitted in a line is1. Isolator2. Circulator3. Directional coupler4. None of theseAnswer : 336. The return loss in a transmission line is a measure of1. Loss of the line2. Standing wave ratio3. Characteristic impedance of the line4. None of these
  164. 164. Answer : 237. The antenna can be considered as1. Matching the source and free space2. Matching the source to the line3. Matching the line and free space4. None of theseAnswer : 338. The free space impedance is approximately equal to1. 177 W2. 277 W
  165. 165. 3. 377 W4. 50 WAnswer : 339. The polarization refers to1. The physical orientation of the radiated wave2. The directional of propagation of the wave3. Direction perpendicular to the propagation of the wave4. None of theseAnswer : 340. If u & e are the permeability and permittivity respectively the characteristic impedance of themedium is given bya. ue
  166. 166. b. Öu/ec. Öe/ud. ÖeuAnswer : 241. The power density at distance ‘r’ from an isotropic radiator with transmitted power P is:1. P/r22. P/2 p r23. P/4 p r24. None of these ` Answer : 3
  167. 167. 42. The carrier in an FM system disappears for the lowest modulation index of:a. 0.5b. 1.0c. 2.4d. 3.5Answer : c43. The difference between phase and frequency modulation:1. Is purely theoretical because they are the same in practice2. Is too great to make the two systems compatible3. Lies in the poorer audio response of phase modulation4. Lies in the different definition of the modulation indexAnswer : 4
  168. 168. 44. The overall noise figure of two cascaded amplifiers is equal to1. The algebraic sum of the two2. The sum of the squares of the two3. The square root of the product of the two4. None of theseAnswer : 445. The noise power output of an amplifier is equal to:1. KTo BFG2. KTo FG3. KTo F/G
  169. 169. 4. KTo / FGAnswer : 146. The effective noise temperature of an amplifier is equal to1. (F + 1) To2. FTo3. (F – 1) To4. None of theseAnswer : 347. The noise figure of an amplifier depends upon1. Its bandwidth2. Its gain
  170. 170. 3. Its operating frequency4. None of these Answer : 448. The velocity of electromagnetic wave in a coaxial cable is1. Equal to the velocity in free space2. Less than the velocity in free space3. Greater than the velocity in free space4. None of these Answer : 249. The standing wave ratio [SWR] in a transmission line:
  171. 171. 1. Is proportional to the load impedance2. Is dependent on the source impedance3. Is a mis-match between the load and line4. Is a measure of its power handling capabilityAnswer : 350. The standing wave ratio (SWR) is unity in a transmission line if1. The load impedance is equal to the characteristic impedance of the line2. The load impedance is twice that of the characteristic impedance3. The load impedance is half of the characteristic impedance of the line4. None of theseAnswer : 1
  172. 172. 51. The standing wave voltage node along a line repeats at the rate of if L is the wave lengtha. L/4b.L/2c.Ld.2LAnswer : 252. FM modulation becomes equivalent to AM modulation if1. FM index is greater than 12. FM index is equal to 13. FM index is very much less than 1
  173. 173. 4. FM index less than or equal to 1Answer : 353. S/N improvement of FM over AM, B is the FM modulation indexa. 3B2b.Bc.2Bd.B/2Answer : a54. Picture transmission in TV employs1. Suppressed carrier modulation2. Vestigial side band
  174. 174. 3. Single side band4. None of theseAnswer : 255. Sound transmission in TV employ1. Amplitude modulation2. Phase modulation3. Frequency modulation4. Pulse amplitude modulationAnswer : 356. One of the following is an indirect way of generating FM this is the:
  175. 175. 1. Reactance FET modulator2. Varacter divide modulator3. Amstrong modulator4. Reactance bipole transistor modulatorAnswer : 357. The modulation index of AM wave is changed from 0 to 1. The transmitted power is1. Un-changed2. Halved3. Doubled4. Increased by 50%Answer : 4
  176. 176. 58. The isotropic antenna is represented by1. Dipole antenna2. Rhombic antenna3. Yagi uda antenna4. No such antenna exists in practiceAnswer : 459. The gain of parabolic reflector antenna is proportional to1. The diameter of the reflector2. Square of the diameter of the reflector3. Aperture area of the feed4. None of these
  177. 177. Answer : 260. The parabolic reflector antenna are generally used to1. Provide high gain2. Provide pencil beam3. Increase bandwidth of operation4. None of theseAnswer : 261. Cassegrain feed is used with a parabolic reflector to1. Increase gain of the system2. Increase the bandwidth of the system3. Reduce the size of the main reflector
  178. 178. 4. Allow the feed to be placed at a convenient pointAnswer : 462. A helical antenna is used for satellite tracking because of its1. Circular polarization2. Maneuverability3. Broad bandwidth4. Good front – to – back ratioAnswer : 163. The discone antenna is1. A useful direction finding antenna
  179. 179. 2. Used as a radar receiving antenna3. Circularly polarized like other circular antenna4. Useful as a VHF receiving antennaAnswer : 464. Waveguides are used mainly for microwave signals because1. They depend on straight line propagation which applies to microwaves only2. Losses would be too heavy at lower frequencies3. There are no generators powerful enough to excite them at lower frequencies4. They would be too bulky at lower frequenciesAnswer : 465. The wavelength in a waveguide
  180. 180. 1. Is greater than in free space2. Depends only on the waveguide dimensions and the free-space wavelength3. Less than the free space wavelength4. Equal to the free space wavelengthAnswer : 166. The dominant mode of propagation is preferres with rectangular waveguide because(indicate falsestatement)1. It leads to the smallest waveguide dimensions2. The resulting impedance can be matched directly to coaxial lines3. It is easier to excite than the other modes4. Propagation of it without any spurious generation can be ensuredAnswer : 2
  181. 181. 67. The velocity of propagation (group velocity) in a waveguide is1. Less than the free space velocity2. Greater than the free space velocity3. Equal to be free space velocity4. None of theseAnswer : 168. A wave can propagate in a waveguide if its cut off wavelength is1. Greater than the free space wavelength2. Less than the free space wavelength3. Equal to be free space wavelength4. None of these
  182. 182. Answer :369. The dominant mode in a rectangular waveguide isa. TE11b. TE10c.TE20d.TM11Answer : 270. The characteristic wave impedance of a waveguide1. Depends on the mode of propagation2. Does not depend on the mode of propagation
  183. 183. 3. Is same as the free space impedance4. None of theseAnswer : 171. A choke flange may be used to couple two waveguides1. To help in the alignment of the waveguides2. Because it is simpler than any other joint3. To compensate the discontinuities at the joint4. To increase the bandwidth of the systemAnswer : 272. Frequencies in the UHF range is normally propagated by means of1. Ground waves
  184. 184. 2. Sky waves3. Surface waves4. Space wavesAnswer : 473. As electromagnetic waves travel in free space, only one of the following can happen to them1. Absorption2. Attenuation3. Reflection4. RefractionAnswer : 2
  185. 185. 74. High frequency waves are1. Absorbed by the F2 layer2. Reflected by the D layer3. Affected by the solar cycle4. Capable of use for long distance communications on the moonAnswer : 375. Indicate which one of following terms applies to troposcatter propagation1. SIDS2. Fading3. Fraday rotation4. Atmospheric stormsAnswer : 2
  186. 186. 76. When microwave signals follow the curvature of the earth, this in known as1. Faraday effect2. Ducting3. Ionospheric reflection4. Tropospheric scatteringAnswer : 277. An ungrounded antenna near the ground:1. Is unlikely to need an earth mat2. Acts as a single antenna of twice the height3. Must be horizontally polarized
  187. 187. 4. Acts as an antenna arrayAnswer : 478. One of the following consists of non-resonant antenna:1. The folded dipole2. The rhombic antenna3. The end fire array4. The broad side arrayAnswer : 279. Balun is:1. A circuit element to connect balance line to unbalanced antenna or line:2. A circuit element to connect balance line to balanced line
  188. 188. 3. A circuit element to connect unbalance line to unbalanced line4. None of theseAnswer : 180. The slotted line is used to measure:1. Standing wave ratio2. Load impedance3. Source impedance4. None of theseAnswer : 181. In amplitude modulation Ec ( 1 + m Sin Wmt) Sin Wot, each side band amplitude will be:
  189. 189. 1. Ecm/22. Ecm3. Ec/m4. 2Ec/mAnswer : 182. The dominant mode in a circular waveguide isa. TE01b.TE11c.TM01d.TM11 Answer : 3
  190. 190. 83. A ferrite is1. A non-conductor with magnetic properties2. An inter metallic compound with particularly good conductivity3. An insulator which heavily attenuates magnetic fields4. A microwave semiconductor invented by faradyAnswer : 184. The maximum power that may be handled by a ferrite component is limited by the1. Curie temperature2. Saturation magnetization3. Line width
  191. 191. 4. Gyro magnetic resonanceAnswer : 185. The isolator is1. Bidirectional2. Unidirectional3. Used to tap the power in a waveguide transmission line4. Used for None of these of the aboveAnswer : 286. Isolator is generally used:1. To protect the high power transmitter2. To protect receiver
  192. 192. 3. To protect the antenna4. To avoid arcing in waveguidesAnswer : 187. A TR tube is used1. To protect the high power transmitter2. To protect receiver3. To avoid arcing in waveguides4. For None of these of the aboveAnswer : 288. Rieke diagrams are used to select best operating conditions for
  193. 193. 1. TWT amplifier2. Klystron oscillator3. Magnetron oscillator4. Cross field amplifiersAnswer : 389. The gain bandwidth product of a microwave transistor FT, is the frequency at which the1. Alpha of the transistor falls by 3 dB2. Beta of the transistor falls by 3 dB3. Beta of the transistor falls to unity4. Power gain of the transistor falls to unityAnswer : 1
  194. 194. 90. The cavity magnetron uses strapping to1. Prevent mode jumping2. Prevent cathode-back heating3. Ensure bunching4. Improve the phase-focussing effect Answer : 491. The transferred – electron bulk effect occurs in1. Germanium2. Gallium arsenide3. Silicon4. Metal semiconductor junction
  195. 195. Answer : 292. One of the following is not used as a microwave mixer or detector1. Crystal diode2. Schottky – barrier diode3. Backward diode4. PIN diodeAnswer : 493. SAW devices may be used as:1. transmission media like stripline2. filters3. UHF amplifiers
  196. 196. 4. Oscillators at millimeter frequenciesAnswer : 294. Surface acoustic waves propagate in:1. Gallium arsenide2. Indium phosphide3. Stripline4. Quartz crystalAnswer : 495. A parametric amplifier has an input and output frequency of 2.25 GHz, and is pumped at 4.5 GHz is a1. Traveling wave amplifier
  197. 197. 2. Degenerate amplifier3. Lower-side band up converter4. Upper-side band up converterAnswer : 296. The negative resistance in a tunnel diode1. Is maximum at the peak point of the characteristic2. Is available between the peak and valley points3. Is maximum at the valley point4. May be improved by the reverse biasAnswer : 297. Microwave links repeaters are typically 50KM apart
  198. 198. 1. Because of atmospheric attenuation2. Because of output tube power limitations3. Because of Earth’s curvature4. To ensure that the applied voltage is not excessiveAnswer : 398. Microwave links are generally preferred to coaxial for television transmission because1. They have less overall phase distortion2. They are cheaper3. Of their greater bandwidths4. Of their relative immunity to impulse noiseAnswer : 1
  199. 199. 99. A geostationary satellite1. Is motionless in space(except for its spin)2. Is not really stationary at all, but orbits the earth with a 24 hour period3. Appears stationary over Earth’s magnetic pole4. Is located at a height of 35800KM to ensure global coverageAnswer : 2100. The geostationary satellite launched by India are called1. INTELSAT2. INSAT3. COMSAT4. MARISAT
  200. 200. Answer : 2101. After a target has been acquired the best scanning system for tracking is1. Nodding2. Spiral3. Conical4. HelicalAnswer : 3102. The Doppler frequency increases as the target1. Approaches the radar2. Recedes the radar
  201. 201. 3. Moves perpendicular to the beam4. Does not depend on the target velocityAnswer : 1103. The Doppler effect is used in (indicate the false statement)1. Moving target plotting on the PPI2. MTI system3. FM Radar4. CW RadarAnswer : 1104. Solution to the blind speed problem is to1. Change the Doppler frequency2. Vary the PRF
  202. 202. 3. Use monopulse4. Use MTIAnswer : 2105. The A-scope displays1. Target position and range2. Target range but not position3. Target position but not range4. Neither range nor position but only velocityAnswer : 2106. In the colour television system the sub carrier frequency in MHz is approximately
  203. 203. a. 3.58b.4.5c. 45.75d. 5.58Answer : a107. In television 4: 3 : represents1. The interlace ratio2. The maximum horizontal deflection3. Aspect ratio4. The ratio of the two diagonals of picture tubeAnswer : 3
  204. 204. 108. Equalizing pulses in TV are sent during the:1. Horizontal blanking2. Vertical blanking3. The serrations4. Horizontal retraceAnswer : 2109. The number of lines per field in Indian television system is:a. 625b. 312.5c. 525d. 262.5
  205. 205. Answer : 2110. The number of frames in Indian TV system is:a. 50b. 60c. 25d.30Answer : a111. In a TV receiver the colour killer:1. Cuts off the chromastages during monochrome reception2. Ensures that no colour is transmitted to monochrome receivers3. Prevents colour overloading
  206. 206. 4. Makes sure that the colour burst is not mistaken for sync pulsesAnswer : 1112. A parametric amplifier must be cooled1. Because parametric amplification generates a lot of hest2. To increase bandwidth3. Because it cannot operate at room temperature4. To improve the noise performanceAnswer : 4113. If the peak transmitted power in a Radar system is increased by a factor of 16, the maximumrange will be increased by a factor ofa. 2

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