1. aipmt–Past papers<br />PHYSICS- UNSOLVED PAPER - 1994<br />
2. SECTION – I (Total Marks : 50)<br />Single Correct Answer Type<br />There are five parts in this question. Four choices are given for each part and one of them is correct. Indicate you choice of the correct answer for each part in your answer-book by writing the letter (a), (b), (c) or (d) whichever is appropriate<br />
3. 01<br />Problem<br />A hollow metallic sphere of radius 10 cm is charged such that potential of its surface is 80 V. The potential at the centre of the sphere would be <br />80 V<br />800 V<br />zero<br />8 V.<br />
4. Problem<br />02<br />Charge q2 is at the centre of a circular path with radius r. Work done in carrying charge q1, one around the equipotential path, would be <br /> a.<br />b.<br />c. zero<br />d. infinite.<br />
5. Problem<br />03<br /> A magnet oscillates, in earth’s magnetic field, with a time-period T. If its mass is quadrupled, then its new time – period will be <br />T/2, motion remaining S.H.M<br />Unaffected but motion is not S.H.M.<br />4T, motion remaining S.H.M.<br />2T, motion remaining S.H.M.<br />
6. Problem<br />04<br />The given figure gives electric lines of force due to two charges q1 and q2. What are the sings of the two charges? <br />q1 is positive but q2 is negative <br />q1 is negative but q2 is positive <br />both are negative <br />both are positive.<br />
7. Problem<br />05<br />A circular loop of area 0.01 m2 carrying a current of 10 A, is held perpendicular to a magnetic field of intensity 0.1 T. The torque acting on the loop is <br />N .m<br />0.8 N.m<br />zero<br />N.m<br />
8. Problem<br />06<br />An electric bulb is rated 60 W, 220 V. The resistance of its filament is <br />870 <br />780 <br />708 <br />807 <br />
9. Problem<br />07<br />Two cables of copper are of equal lengths. One of them has a single wire of area of cross- section A, while other has 10 wires of Cross-sectional area A/10 each. Give their suitability for transporting A.C. and D.C.<br />Only multiple strands for A.C., either for D.C.<br />Only multiple strands for A.C., only single strand for D.C.<br />Only single strand for D.C., either for A.C.<br />Only single strand for A.C., either for D.C.<br />
10. Problem<br />08<br />An L-C-R circuit is connected to a source of A.C. current, At resonance, the phase difference between the applied voltage and the current in the circuit, is <br />a.<br />b. zero<br />c. /4<br />d. /2<br />
11. Problem<br />09<br />A wire 50 cm long and 1 mm2 in cross –section carries a current of 4 A when connected to a 2 V battery. The resistivity of the wire is <br /> <br />4 x 10-6<br />1x 10-6 <br />2x 10-7<br />5 x10-7 .<br />
12. Problem<br />10<br />Six resistors of 3 each are connected along the sides of a hexagon and three resistor of 6 each are connected along AC, AD and AE as shown in the figure. The equivalent resistance between A and B is equal to <br />2 <br />6 <br />3 <br />9 <br />
13. Problem<br />11<br />A small source of light is 4 m below the surface of water of refractive index 5/3. In order to cut off all the light, coming out of water surface, minimum diameter of the disc placed on the surface of water is <br />a. 6 m <br />b. <br />c. 3m<br />d. 4m<br />
14. Problem<br />12<br />In an A.C. circuit, Irms and andI0 and related as <br /> a.<br />b. <br />c.<br /> d.<br />
15. Problem<br />13<br />Identify the set in which all the three materials are good conductors of electricity <br />Cu, Hg and NaCl<br />Cu, Ge and Hg <br />Cu, Ag and Au<br />Cu, Si and diamond.<br />
16. Problem<br />14<br /> A flow of 107 electrons per second in a conducting wire constitutes a current of <br />1.6 x 10-12 A<br />1.6 x 1026 A<br />1.6 x 10-26 A<br />1.6 x 1012 A.<br />
17. Problem<br />15<br />The current I in an A.C. circuit inductance coil varies with time according to the graph given below. <br />Which one of the following graphs gives the variation of voltage with time?<br />a.<br />b. <br />c.<br />d.<br />
18. Problem<br />16<br />A source of frequency v gives 5 beats/second when sounded with a source of frequency 200 Hz. The second harmonic of frequency 2v of source gives 10 beats/second when sounded with a source of frequency 420 Hz. The value of v is <br />205 Hz<br />195 Hz.<br />200 Hz<br />210 Hz.<br />
19. Problem<br />17<br />I A loaded vertical spring executes S.H.M. with a time period of 4 sec. The difference between the kinetic energy and potential energy of this system varies with a period of <br />2 sec<br />1 sec<br />8 sec<br />5sec<br />
20. Problem<br />18<br />Which of the following is simple harmonic motion?<br />Particle moving in a circle with uniform speed <br />Wave moving through a string fixed at both ends<br />Earth spinning about its axis<br />Ball bouncing between two rigid vertical walls.<br />
21. Problem<br />19<br />Ray optics is valid, when characteristic dimensions are<br /> <br />Much smaller than the wavelength of light <br />Of the same order as the wavelength of light <br />Of the order of one millimeter<br />Much larger than the wavelength of light.<br />
22. Problem<br />20<br />Which of the following electromagnetic radiations have the smaller wavelength ? <br />X-rays<br />y-rays<br />UV waves<br />Microwaves.<br />
23. Problem<br />21<br />The blue colour of the sky is due to the phenomenon of<br /> <br />Scattering <br />Dispersion <br />Reflection <br />Refraction.<br />
24. Problem<br />22<br />Which one of the following gates correspond to the truth table given below? <br />NAND<br />NOR<br />XOR<br />OR<br />
25. Problem<br />23<br />An electric dipole of moment p is placed in the position of stable equilibrium in uniform electric field of intensity E. This is rotated through an angle from the initial position. The potential energy of the electric dipole in the final position is <br />-pEcos<br />pE (1- cos )<br />pEcos<br />pE sin .<br />
26. Problem<br />24<br />In an adiabatic change, the pressure and temperature of a monatomic gas are related as where C equals <br />a.<br /> b.<br />c.<br />d.<br />
27. Problem<br />25<br />For lenses of focal length 15 cm and 150 cm are available for making a telescope. To produce the largest magnification, the focal length of the eyepiece should be <br />+ 15 cm<br />+ 150 cm<br />150 cm<br />-15 cm.<br />
28. Problem<br />26<br />A stationary wave is represented by where y and A are in millimeters, t is in second and x is meters. The velocity of the wave is <br />104 m/s<br />not derivable <br />1 m/s<br />102 m/s<br />
29. Problem<br />27<br />The oscillating electric and magnetic vectors of an e.m. wave are oriented along <br />Mutually perpendicular directions and are in phase<br />Mutually perpendicular directions but has a phase difference of 900<br />The same direction and are in phase <br />The same direction but have a phase difference of 900<br />
30. Problem<br />28<br />The displacement –time graph of a moving particle is shown below. The instantaneous velocity of the particle in negative at the point <br /> E<br />F<br />C<br /> D<br />
31. Problem<br />29<br />A solid spherical ball rolls on a table. Ratio of its rotational kinetic energy to total kinetic energy is<br />a.<br />b.<br />c.<br />d. <br />
32. Problem<br />30<br />A particle executes S.H.M along x-axis. The force acting on it is given by <br />A cos (kx)<br />Ae-kx<br />Akx<br />Akx.<br />
33. Problem<br />31<br />Two identical balls A and B collide head on elastically. If velocities of A and B, before the collision, are +0.5 m/s and –0.3 m/s respectively, then their velocities, after the collision, are respectively <br />-0.5 m/s and + 0.3 m/s<br />+ 0.5 m/s and + 0.3 m/s<br />+ 0.3 m/s and – 0.5 m/s<br />-0.3 m/s and + 0.5 m/s.<br />
34. Problem<br />32<br />A seconds pendulum is mounted in a rocket. Its period of oscillation <br /> will decrease when rocket is <br />Moving down with uniform acceleration <br />Moving around the earth in geostationary orbit <br />Moving up with uniform velocity <br />Moving up with uniform acceleration. Decline <br />
35. Problem<br />33<br />A wave of frequency 100 Hz travels along a string towards its fixed end. When this wave travels back, after refection, a node is formed at a distance of 10 cm from the fixed end. The speed of the wave (incident and reflected ) is <br />20 m/s<br />40 m/s<br />6m/s<br />10 m/s.<br />
36. Problem<br />34<br />A body of mass 5 kg hangs from a spring and oscillates with a time period of 2 seconds. If the ball is removed, the length of the spring will decrease by <br />g/k meters<br />k/g meters<br />2 meters<br />g meters.<br />
37. Problem<br />35<br />Which one of the following represents a wave?<br />a.<br />b.<br />c.<br />d.<br />
38. Problem<br />36<br />In a rocket, fuel burns at the rate of 1 kg/s. This fuel is ejected from the rocket with a velocity of 60 km/s. This exerts a force on the rocket equal to <br /> <br />6000 N<br />60000 N<br />60 N<br />600 N <br />
39. Problem<br />37<br />A satellite in force – free space sweeps stationary interplanetary dust at a rate of where M is mass and v is the speed of satellite and is a constant. The acceleration of satellite is <br /> a.<br />b.<br />c.<br />d.<br />
40. Problem<br />38<br />If the gravitational force between tow objects were proportional to 1/R (and not as 1/R2), where R is the distance between them, then a particle in a circular path (under such a force ) would have its orbital speed v, proportional to <br />R <br />R0(independent of R)<br />1/R2<br />1/R.<br />
41. Problem<br />39<br />The distance of two planets from the sun are 1013 m and 1012 m respectively. The ratio of time periods of the planets is <br />a.<br />b.10 <br />c. 10<br /> d.1/<br />
42. Problem<br />40<br />The radius of earth is about 6400 km and that of mars is 3200 km. The mass of the earth is about 10 times mass of mars. An object weighs 200 N on the surface of earth. Its weight on the surface of mars will be <br /> 20 N<br />6N<br />80N<br />40 N<br />
43. Problem<br />41<br />When a body moves with a constant speed along a circle<br /> <br />No work is done on it <br />No acceleration is produced in it<br />Its velocity remains constant<br />No force acts on it<br />
44. Problem<br />42<br />The velocity of train increases uniformly from 20 km/h to 60 km/h in 4 hours. The distance traveled by the train during this period is <br />160 km<br />180 km<br />100 km<br />120 km.<br />
45. Problem<br />43<br />A position dependent force, F = 7 –2x + 3x2 N acts on a small body of mass 2 kg and displaces if from the work done in joules is <br />135<br />270<br />35<br />70.<br />
46. Problem<br />44<br />A particle moves along a straight line such that its displacement at any time t is given by meters. The velocity when the acceleration is zero is <br />3 m/s<br />42 m/s<br />-9 m/s<br />-15 m/s.<br />
47. Problem<br />45<br />a boat is sent across a river with a velocity of 8 km/h. If the resultant velocity of boat is 10 km/h, then velocity of the river is <br />8km/h<br />10km/h<br />12.8 km/h<br />6 km/h.<br />
48. Problem<br />46<br />A car accelerates from rest at a constant rate for some time after which it decelerates at a constant rate and comes to rest. If total time elapsed is t, then maximum velocity acquired by car will be<br />a.<br /> b. <br />c.<br />d.<br />
49. Problem<br />47<br />The kinetic energy acquired by a mass m in traveling distance d. starting from rest, under the action of a constant force is directly proportional to <br />a. m<br /> b. <br />c.<br />d.1/<br />
50. Problem<br />48<br />A body, constrained to move in y-direction, is subjected to a force given by The work done by this force in moving the body through a distance of m along y-axis, is <br />150 J<br />20 J<br />190 J<br />160 J<br />
51. Problem<br />49<br />The angle between the two vectors and will be <br />900<br />1800<br />zero<br />450.<br />
52. Problem<br />50<br />Which of the following has the dimensions of pressure?<br /> <br />MLT-2<br />ML-1T-2<br />ML-2T-2<br />M-1L-1.<br />
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