The document is about sample physics questions for an entrance exam for admission to BSc Agriculture programs in Tamil Nadu Agricultural University and other agricultural universities. It contains 33 multiple choice physics questions on topics like mechanics, electricity, waves, optics and thermodynamics along with explanations for the answers. The questions are provided in both English and Tamil.

1. ICAR –AIEEA EXAMINATION FOR ALL INDIA LEVEL ENTRANCE EXAMINATION
FOR ADMITTING STUDENTS TO Bsc,(Agriculture)in TNAU AND OTHER
AGRICULTURAL UNIVERSITIES.
MODEL QUESTIONS -PHYSICS
வேளாண்மை பட்டப்படிப்பில் படிப்பதற்கானஅகில இந்திய
அளேில்நுமைவு வதர்வு
ைாதிரி ேினாேிமட- இயற்பியல் பாடம்
By S.Kannan
Agricultural Officer from Thiruvarur District
(9965563563)
1)The working principle of a washing machine is
A) reverse
osmosis
B) diffusion
C) centrifugation D) dialysis
Answer: C) centrifugation
Explanation:
The working principle of a washing machine is centrifugation.
2)Nuclear sizes are expressed in a unit named

2. A) Fermi B) Angstrom
C) Newton D) Tesla
Answer: A) Fermi
Explanation:
Nuclear sizes are expressed in a unit called "Fermi" which is a unit of length equal
to 10−15
metre (one femtometre), used in nuclear physics. It is similar to the
diameter of a proton.
3)The speed of light will be minimum while passing through
A) water B) vaccum
C) air D) glass
Answer: D) glass
Explanation:
4)Which of the following is not a vector quantity?
A) speed B) velocity
C) torque D) displacement
Answer: A) speed
Explanation:

3. A vector quantity is a quantity which has both magnitude and direction. Here in the
given options, speed is a scalar quantity but not the vector quantity.
5)The most suitable unit for expressing nuclear radius is
A) micro B) nanometre
C) fermi D) angstrom
Answer: C) fermi
Explanation:
5)It is more difficult to walk on ice than on a concrete road because
A) there is very
little friction between
the ice and feet
pressing it
B) ice is soft
when compared to
concrete
C) there is more
friction between the
ice and feer
D) None of these
Answer: A) there is very little friction between the ice and feet pressing it
Explanation:
It is the friction between the feet and the ground that helps us to walk. Without this
friction we would slip and fall
6) Two electric bulbs marked 25W – 220V and 100W – 220V are connected in
series to a 440Vsupply. Which of the bulbs will fuse?
A) 25 W B) Both
C) 100 W D) Neither
Answer: A) 25 W
Explanation:
Resistances of both the bulbs are

4. R1=V^2/P1 = 220^2/25
R2 = V^2/P2 = 220^2/100
Hence R1gt ; R2R1gt ; R2
When connected in series, the voltages divide in them in the ratio of their
resistances. The voltage of 440 V devides in such a way that voltage across 25 w
bulb will be more than 220 V. Hence 25 w bulb will fuse.
7)Rain drops acquire spherical shape due to
A) viscosity B) surface tension
C) friction D) elasticity
Answer: B) surface tension
Explanation:
The Surface tension pulls the surface of the drop equally at all points thus produces
the spherical shape having the minimum surface area .
8) An air bubble in water will act like a
A) convex lens B) convex mirror
C) concave lens D) concave mirror
Answer: C) concave lens
9) Temperature can be expressed as derived quantity in terms of any of the
following
A) length and mass B) mass and time
C) length,mass and time D) in terms of none
Answer: D) in terms of none

5. 10) A solid ball of metal has a spherical cavity inside it. When the ball is heated
the volume of the cavity will
A) increase B) decrease
C) remain unaffected
D) have its shape
changed
Answer: A) increase
Explanation:
The metal ball can be considered to be made up of several layers of thinner ones.
On heating each of these layers will increase in radius. As the inner most layer also
increases its radius, the volume inside it i.e, the volume of the hollow portion will
also increase.
11) Which of the following is not the unit of time
A) Parallactic second B) Micro Second
C) Leap year D) Solar day
Answer: A) Parallactic second
12) If a sound travels from air to water, the quantity that remain unchanged is
A) velocity B) frequency

6. C) wavelength D) amplitude
Answer: B) frequency
13) When a bottle of perfume is opened in one corner of a room the smell spreads
soon throughout the room. This is an example of
A) surface tension B) capillarity
C) viscosity D) diffusion
Answer: D) diffusion
Explanation:
Diffusion is the spreading - mixing of gases through molecular motion.
14) What is the SI unit of pressure
A) Pascal B) Dyne
C) Newton D) Jule
Answer: A) Pascal
15) The basic reason for the extraordinary sparkle of suitably cut diamond is that
A) it has well defined
cleavage planes
B) it has a very high
transparency
C) it has a very high
refractive index
D) it is very hard
Answer: C) it has a very high refractive index

7. 16) Pieces of camphor placed on water move about rapidly. This is because of
A) diffusion B) viscosity
C) surface tension D) capillarity
Answer: C) surface tension
Explanation:
The Camphor slowly dissolves in the water lowering the latter's surface tension in
the immediate neighbourhood. The stronger pull exerted by the uncontaminated
portion of water brings about a movement of the surface and the camphor particles
are carried along with it. When after sometime the whole surface settles for the
reduced tension, the movement of the camphor too short.
17) Air pressure is usually highest when the air is
A) warm and moist B) cool and dry
C) warm and dry D) cool and moist
Answer: D) cool and moist
Explanation:
Both warmth and moisture reduce the density of air and hence its pressure.
18) The minimum number of Non zero non collinear vectors required to produce a
zero vector is
A) 3 B) 2
C) 4 D) 1
Answer: A) 3

8. 19) The core of an electromagnet is made of soft iron because soft iron has
A) small susceptibility
and small retentivity
B) large susceptibility
and small retentivity
C) large density and
large retentivity
D) small density and
large retentivity
Answer: B) large susceptibility and small retentivity
20) A bucket of water is hung from a spring balance. A piece of iron is suspended
in the water without touching the sides or touching the bottom of the bucket. The
reading of the spring balance
A) will increase B) will decrease
C) does not change
D) varies with the
increase of depth of the
immersion of the iron piece
Answer: A) will increase
Explanation:
When the piece of iron is lowered into the water, the water level in the bucket
increases. And so the pressure at the bottom of bucket also increases. Thus the total
thrust at the botto also increases. Therefore the spring balance reading increases.
21) The base of an electric iron is brightly polished mainly
A) to make it smooth
and frictionless
B) to make it rust-proof
C) to reduce heat loss by
radiation
D) to make it more
durable

9. Answer: C) to reduce heat loss by radiation
Explanation:
Polished surfaces are poor radiators of heat. So loss of heat on that account is
reduced and the electric iron remains hotter than otherwise.
22) Which is best used as a sound absorbing material in partition walls ?
A) Stone chips B) Steel
C) Glass - wool D) Glass pieces
Answer: C) Glass - wool
Explanation:
Materials that do not transfer mechanical energy well. These tend to be
soft,flexible, low density, and with high surface area to linear area ratios.
24) If a band is played on the moon the sound will
A) reverberate B) be heard by us faintly
C) be heard upto 10km
from it
D) not be heard at any
distance at all from it
Answer: D) not be heard at any distance at all from it
Explanation:
As there is no atmosphere surrounding the moon, the sound from any band that is
played there cannot travel outwards there is no material medium surrounding it for
its propagation.
25) The rate of change of linear momentum of a body falling freely under gravity
is equal to it's ____ ?
A) Kinetic Energy B) Weight

10. C) Potential Energy D) Impulse
Answer: B) Weight
Explanation:
Rate of change of impulse equals the force . In case of freely falling body the only
force is the weight.
26) The working of the quartz crystal in the watch is based on the
A) Piezo - electric Effect B) Edison Effect
C) Photoelectric Effect D) Johnson Effect
Answer: A) Piezo - electric Effect
27) Ultrasonic waves are used for stirring liquid solutions because they
A) do not produce noise
during the operation
B) are easy to produce
C) can produce perfectly
homogeneous solutions
D) do not produce
chemical reactions in the
solution
Answer: C) can produce perfectly homogeneous solutions
28) One astronomical unit is the average distance between
A) Earth and the Sun B) Earth and the Moon
C) Jupiter and the Sun D) Pluto and the Sun
Answer: A) Earth and the Sun
29) Masses of stars and galaxies are usually expressed in terms of

11. A) neutron mass B) earth's mass
C) solar mass D) lunar mass
Answer: C) solar mass
30) Sound following a flash of lightning is called
A) Stoning B) Bolting
C) Thunder D) Cloud clash
Answer: C) Thunder
Explanation:
The Sound Following the flash of lighting is because of Thunder.
Lightning is seen earlier than thunder because light travels much faster than
sound.
The roar of thunder is the result of a shock wave produced when lightning super-
heats the air through which it passes, causing that air to expand very rapidly. This
rapid expansion of air creates a shock wave that travels outward at close to the
speed of sound.
31) A potentiometer wire is 100 cm long and a constant potential difference is
maintained across it. Two cells are connected in series first to support one another
and then in opposite direction. The balance points are obtained at 50 cm and 10 cm
from the positive end of the wire in the two cases. The ratio of the emf's is :
A) 3:4 B) 5:4
C) 5:1 D) 3:2
Answer: D) 3:2

12. Explanation:
In series : E1 + E2 = K(50)
In parallel : E1 - E2 = K(10)
E1 + E2 / E1 - E2 = 5/1
=> E1/E2 = 3/2
The emf's are in the ratio of 3:2.
32) Ball bearings are used in cycles, scooters etc to
A) Increase the friction
between the wheel and the
axle
B) Reduce the friction
between the wheel and the
axle
C) Reduce the friction
between ground and the
whee
D) None of the above
Answer: B) Reduce the friction between the wheel and the axle
33) Pick out the only scalar quantity
A) power B) Electric field
C) magnetic momentum D) average velocity
Answer: A) power
34) To produce deflection in a television picture tube:

13. A) an electric field is
used
B) a magnetic field is
used
C) both electric and
magnetic field are used
D) none of the above
Answer: B) a magnetic field is used
35) Which of the following physical quantities do not have same dimensions
A) Force and Pressure B) Work and Energy
C) Impulse and
momentum
D) Weight and Force
Answer: A) Force and Pressure
36) The ringing of an electric bell in an enclosed evacuated glass bell jar is not
heard outside because
A) the ringing is not
loud enough
B) the glass of the bell jar
absorbs the sound waves
C) the bell jar is too
small
D) there is no air or any
other gas in the bell jar
Answer: D) there is no air or any other gas in the bell jar
38) Optical fiber works on the principle of
A) Scattering B) interference
C) total internal
reflection
D) refraction
Answer: C) total internal reflection

14. 39) If lift is going up with acceleration, the apparent weight of a body is
A) may be more or less
than true weight
B) more than the true
weight
C) less than the true
weight
D) equal to the true
weight
Answer: B) more than the true weight
40) Skating on ice is possible because
A) the surface of ice is
smooth
B) ice is cold
C) the pressure on the
ice due to skate melts the ice
by lowering its melting
point forming a thin film of
water
D) the pressure on the ice
due to skate raises its
melting point
Answer: C) the pressure on the ice due to skate melts the ice by lowering its
melting point forming a thin film of water
Explanation:
Here is a case of lowering of melting point of ice with increase of pressure
41) If a carrier wave of 1000 kHz is used to carry the signal, the length of
transmitting antenna will be equal to _____ ?
A) 300 m B) 30 m
C) 3 m D) 0.3 m
Answer: A) 300 m
Explanation:

15. h = = 3 × 108
/106
= 300 m
42) The information of brilliant colors in a thin soap film is a consequence of the
phenomena of
A) Polarization and
interference
B) Diffraction and
dispersion
C) Multiple refraction
and dispersion
D) Multiple reflection
and interference
Answer: D) Multiple reflection and interference
43) Formation of shadows can be explained by
A) rectilinear
propagation of light
B) reflection
C) refraction
D) total internal
reflection
Answer: A) rectilinear propagation of light
Explanation:
In this position, the head light will be at the principal focus so that the rays of light
falling on the cancave mirror will be rendered parallel
44) The image of an object formed on the retina of the eye is
A) virtual and upright B) virtual and inverted
C) real and inverted D) Real and upright
Answer: C) real and inverted
Explanation:

16. Although the image is inverted the mental interpretation of the effect on the retina
is as though it is erect
46A boat loaded with rocks floats in the middle of a swimming pool. A man in the
boat throws the rocks overboard. The level of water in the pool will
A) increase B) decrease
C) remains the same
D) first decrease and then
increase
Answer: B) decrease
Explanation:
Let M and m grams be the mass of boat + rock in it. By law of floatation(M+m)
grams of water will be displaced. This has a volume of (M+m)cc. That means the
level of water in pool has risen up by (M+m)cc with the boat + rock when it is
floating. If the rocks in the boat are thrown not into the pool but outside, the weight
left is only M grams the weight of the boat. This will have displaced M cc of water
only i.e less water than in the case of loaded boat. But if the rocks are put in the
water in the pool and not outside, then the water in the pool will rise not only by M
cc on account of empty boat but also by a volume of the stone put into it. This
volume will be mdmdwhere m is the mass of rock and d density of rock.
Now mdmd is < m. Thus the total rise will be (M+md)M+mdwhich is < M + m
As there is no medium inside the bell jar, sound cannot travel
45) In a freezer ice cubes will be formed more quickly in trays made of
A) rubber B) plastic
C) aluminium D) wood
Answer: C) aluminium
Explanation:

17. Aluminium being a good conductor of heat conducts away the heat from the
substance quite easily and causes quick freezing.
46) What is the full form of "RADAR" ?
A) Radio Detecting and
Ranging
B) Region Device and
Ranging
C) Radio Detect and
Rangs
D) Radio Device and
Ranging
Answer: A) Radio Detecting and Ranging
47) Mirage is an example of
A) Reflection of light &
Refraction of light
B) Dispersion of light
C) Total Internal
Reflection
D) Refraction of light &
Total Internal Reflection of
light
Answer: D) Refraction of light & Total Internal Reflection of light
Explanation:
A Mirage is a naturally occurring optical phenomenon in which light rays bend to
produce a displaced image of distant objects or the sky.
▪ It is caused due to Total internal Reflection.
▪ It is an optical illusion observed in deserts or hot summer days due to
which a person sees a pond of water some distance ahead of him in which
the surrounding objects appear inverted.
How Mirage Forms::
1. The temperature of other layers of atmosphere goes on decreasing as we go up.
2. Therefore density and refractive index of air changes as one goes up.
3. Thus a ray of light,gets refracted more and more away from the normal.

18. 4. At a particular angle when a ray of light exceeds critical angle, total internal
reflection takes place and ray of light gets reflected in the same medium.
5. when the reflected ray reaches our eye, it appears as coming from tree or sky .
6. Hence the inverted image of tree creates an impression from a pond of water.
48) Total internal reflection can take place when light travels from
A) Air to glass B) Air to water
C) Water to glass D) Diamond to glass
Answer: D) Diamond to glass
49) When body is accelerated
A) its velocity never
changes
B) its speed always
changes
C) its direction always
changes
D) its speed may or
maynot change
Answer: D) its speed may or maynot change
50) The capacity of a pure capacitor is 1 farad. In D.C circuit, its effective
resistance will be
A) Zero B) Infinite
C) 1 Ohm D) 1/2 Ohm
Answer: B) Infinite
51) A ball is thrown vertically upwards. Assuming the air resistance to be constant
and cosiderable:
A) the time of ascent <
the time of descent
B) the time of ascent >
the time of descent

19. C) the time of ascent =
the time of descent
D) none of these
Answer: A) the time of ascent < the time of descent
52) Erg cross Sec is the unit of
A) Angular momentum B) Linear Momentum
C) Planck's constant D) Energy
Answer: C) Planck's constant
53) The direction of heat flow between two objects depends on
A) Their masses B) Their heat contents
C) Their temperatures
D) Whether they are in
solid, liquid or gaseous state
Answer: C) Their temperatures
Explanation:
Heat always flows from a body at higher temperature to a body at a lower
temperature.
54) Where should a boat compass be mounted?
A) near magnet B) near iron
C) away from electrical
wiring
D) All the above
Answer: C) away from electrical wiring
Explanation:
A compass, which is used to assist in navigation, is an instrument that shows
magnetic north. You must apply a correction to determine the direction of true

20. north. The ability to steer a boat by a compass is useful if land is out of sight,
visibility is reduced, or the boat operator is disoriented.
Mount a boat compass away from iron, magnets, and electrical wiring and
equipment.
55) Quality of transmission depends upon
A) Nature of signal only
B) Nature of medium
only
C) Both (A) and (B) D) Neither A nor B
Answer: C) Both (A) and (B)
Explanation:
Quality of transmission is governed both by nature of signal and nature of
communication channel/medium
56) A disk and a sphere of same radius but different masses roll on two inclined
planes of the same altitude and length. Which one of the two objects gets to the
bottom of the plane first ?
A) Depends on their
masses
B) Sphere
C) Disk
D) Both reach at the
same time
Answer: B) Sphere
Explanation:
Time does not depend on mass, else
T ∞ (1 + k2R2)−−−−−−−−−√T ∞ 1 + k2R2

21. k2R2k2R2=> is least for 'sphere' and
hence least time is taken by sphere.
56) A man jumping out of a moving train is thrown
A) forward B) backward
C) sidewaqys D) None of these
Answer: A) forward
Explanation:
At the time of jumping out he has the same velocity as the moving train
57) A piece of ice is floating in water kept in a beaker. When all the ice melts the
level of water will
A) first rise and then fall B) fall
C) remain the same D) rise
Answer: C) remain the same
Explanation:
The submerged portion of the ice on melting shrinks a little in volume. so the level
of water goes down a little.But this is just made up by the water added by the
melting of upper portion. Addition is equal to the Shrinkage. Hence level is
unchanged.
58) In very cold countries alcohol is used as a thermometric liquid because
A) alcohol is a poor
conductor of heat
B) alcohol can be
coloured for its level to be
seen easily
C) its freezing point is
very low
D) it will not stick to the
glass tube
Answer: C) its freezing point is very low

22. Explanation:
Alcohol has a freezing point as low as −117oC-117oC. So it won't freeze even in
very cold countries.
59) Fish and other aquatic creatures can live inside a deep frozen pond because
A) fish are cold-blooded
animals
B) ice is a bad conductor
of heat
C) there will always be
water just beneath the ice
level
D) they can adapt
themselves to live in ice
Answer: C) there will always be water just beneath the ice level
Explanation:
Water has the maximum density at 4oC4oC. So at this temperature, it sinks down
to bottom and stays here. If it cools further, it will become less dense and move up.
So while the upper layers can cool enough to form ice, the bottom layers remain as
water at 4oC4oC .
Therefore, (C) is correct.
60) At the Curie temperature, the ferromagnetic materials get converted into
A) Diamagnetic
materials
B) Non-magnetic
materials
C) Paramagnetic
materials
D) None of the others
Answer: C) Paramagnetic materials
61) The quality of sound produced by an instrument depends on the

23. A) Frequency B) Intensity
C) Number of overtones D) None of these
Answer: C) Number of overtones
62) 1 Joule is Equal to
A) 10^3 ergs B) 10^6 ergs
C) 10^7 ergs D) 10^5 ergs
Answer: C) 10^7 ergs
Explanation:
1 Joule = 107 ergs107 ergs = 0.000239 Kilo Calories.
▪ Joule is the Unit of Energy.
Joule is equal to Energy transferred to an object when a force of One Newton acts
on that object in the direction of its motion through a distance of one metre.(1 N-
m)
63)On the Kelvin scale ,the melting point of ice is
A) 373K B) 100K
C) 273K D) 0 K
Answer: C) 273K
64) No current will flow between two charged bodies if they have the same
A) resistance B) charge

24. C) potential D) charge/ potential ratio
Answer: C) potential
Explanation:
An electric charge always flows from a body at higher potential to a body at a
lower potential irrespective of the amounts of charges contained in them. In the
question , no current flows. So there is no potential difference.
65) Water has maximum density at............
A) 0 C B) -15 C
C) 4 C D) 15 C
Answer: C) 4 C
66) When one enters a dark room after being in bright light one is not able to see
anything clearly for a while because
A) the retina of the eye
moves forward
B) the retina of the eye
moves backward
C) the iris is unable to
dilate the pupil immediately
to be able to see things
D) the eye has no power
of accommodation
Answer: C) the iris is unable to dilate the pupil immediately to be able to see
things
Explanation:
The size of the pupil of the eye automatically adjusts itself according to the
intensity of light passing through it;if the intensity is more , the size is less, if less,
it is more. So in our case the pupil should dilate i.e, increase in size to be able to

25. see in the dark . This switchover takes sometime. But here the entry into the dark
room is immediate . So the eye has no time to adjust itself and hence is not able to
see at all for a while.
67) Energy is continuously generated in the sun due to
A) Nuclear fusion B) Nuclear fission
C) Radioactivity D) Artificial radioactivity
Answer: A) Nuclear fusion
68) A dynamometer wattmeter can be used for
A) Only Direct Current B) Only Active Current
C) Both A & B D) None of the above
Answer: C) Both A & B
Explanation:
A dynamometer wattmeter can be used for measuring both A.C and D.C currents.

26. 69) When light enters from air to water, then its
A) frequency increases
and speed decreases
B) frequency is same but
the wavelength is smaller in
water than in air
C) frequency is same but
the wavelength is larger in
water than in air
D) frequency and speed
both decreases
Answer: B) frequency is same but the wavelength is smaller in water than in air
70) The rotational effect of a force on a body about an axis of rotation is described
in terms of
A) Centre of gravity B) Centripetal force
C) Centrifugal force D) Moment of force
Answer: D) Moment of force
71) Hydrogen atom is excited from ground state to another state with principal
quantum number equal to 4. Then the number of spectral lines in the emission
spectra will be
A) 2 B) 6
C) 5 D) 3
Answer: B) 6
Explanation:
Number of spectral lines from a state n to ground state is
n(n-1)/2 = 6
72) Decibel is the unit of

27. A) speed of light B) intensity of sound
C) intensity of heat D) None of these
Answer: B) intensity of sound
73) Two bodies A and B are of same mass and same amount of heat is given to
both of them. If the temperature of A increases more than that of B because of heat
addition, then
A) the specific heat
capacity of A is more than
that of B
B) the specific heat
capacity of A is less than that
of B
C) both A and B have
the same specific heat
capacity but A has greater
thermal conductivity
D) both A and B the
same specific heat capacity
but B has greater thermal
conductivity
Answer: B) the specific heat capacity of A is less than that of B
74) Light year is a unit of
A) time B) speed of light
C) distance D) mass
Answer: C) distance
75) Water kept in an earthen pot is less cool on rainy days than in summer because
during the rainy days
A) the pores in the pot
are closed
B) rain water stops
oozing out from the pores
C) the water that oozes D) surface of the pot

28. out does not evaporate
quickely because of the
large percent age of
moisture in the air
becomes damp
Answer: C) the water that oozes out does not evaporate quickely because of the
large percent age of moisture in the air
Explanation:
To evaporate the water that oozes out, heat is required. Part of this heat is taken
from the water inside which therefore become cool. Therefore (C) is correct. Here
evaporation is less, so cooling too is less.
76) Which of the following is a vector quantity
A) momentum B) pressure
C) Energy D) work
Answer: A) momentum
77) Unit of solid angle is
A) degree B) radian
C) steradian D) radian second
Answer: C) steradian
78) In a Cinema hall, the distance between the projector and the screen is increased
by 2%. Then the intensity of illumination on the screen is
A) decreased by 2% B) decreased by 4%
C) increased by 2% D) increased by 4%

29. Answer: B) decreased by 4%
79) Which is the point from where an azimuth originates?
A) South B) North
C) East D) West
Answer: B) North
Explanation:
The azimuth originates at true North i.e, the azimuth originates from the north
point. It is a measure of how far an object forms the observer's north point.
Azimuth is a technical mapping term which is used to describe the direction of an
angle between north and south on a compass circle through which the circle line
passes. It is the most common military method to express direction. When using an
azimuth, the point from which the azimuth originates is the center of an imaginary
circle.
80) When white light passes through a glass prism we get a spectrum on the other
side of the prism. In the emergent beam the ray which is deviated least is
A) the violet ray B) the red ray
C) the green ray D) the blue ray
Answer: B) the red ray
Explanation:
Red is deviated the least and violet the most
81) which of the following physical quantity is dimensionless
A) angle B) strain

30. C) specific gravity D) all of these
Answer: D) all of these
82) A convex mirror is used to form an image of a real object. The image
A) is diminished in size B) is erect
C) always lies between
the pole and the focus
D) all of the above
Answer: D) all of the above
83) Which of the following is a scalar quantity
A) electric current B) electric field
C) Acceleration D) linear momentum
Answer: A) electric current
Explanation:
A Scalar quantity is a quantity that has only magnitude but no direction as like
vector.
Here in the given options, electric current is the only one which is scalar.
84) A person is sitting in a moving train and is facing the engine. He tosses up a
coin and the cion fals behind him. It can be concluded that the train is moving:
A) forward and loosing
speed
B) forward and gaining
speed
C) forward and uniform D) backward with

31. speed uniform speed
Answer: B) forward and gaining speed
85) What type of electromagnetic radiation is used in the remote control of a
television?
A) Ultraviolet B) Visible
C) Infrared D) None of the above
Answer: C) Infrared
86) When a steel ball is placed on the surface of mercury, it does not sink because
A) of the surface tension
of mercury
B) mercury is a semisolid
C) of the high viscosity
of mercury
D) the density of mercury
is greater than that of steel
Answer: D) the density of mercury is greater than that of steel
Explanation:
A solid sinks in a liquid if its density is greater than that of the liquid. if less, it
floats
87) Which of the following is the fastest communication channel?
A) Microwave B) Optical fiber
C) Radio wave
D) All are operating at
nearly the same propagation
speed
Answer: A) Microwave

32. Explanation:
A microwave is the fastest communication channel whereas Optical fiber is a way
of transferring data not a way of communication.
88) Why does'nt the hydrogen atom emit X-rays?
A) It is very small in
size
B) It has only one
electron
C) Its energy levels are
very close to each other
D) it is highly
electropositive
Answer: C) Its energy levels are very close to each other
Explanation:
For an atom to emit X-rays it should have difference in energy levels
89) If a body weighs 12N on the surface of the earth, how much will it weigh on
the surface of the moon where acceleration due to gravity is only one-sixth of that
on earth's surface?
A) 12N B) 2N
C) 10N D) 6N
Answer: B) 2N
Explanation:
Weight is mass x g. Since mass is constant and g is only 16th16thof that on the
earth. The weight on the moon is only 16th16th of that on the earth. Therefore 2N
i.e (b) is the answer.
90) The inability of a body to change its state of rest or uniform motion along a
straight line is called its

33. A) momentum B) velocity
C) acceleration D) inertia
Answer: D) inertia
Flows out of Newton's first law of motion.
91) A cyclist leans inwards when he is negotiating a curve so that
A) he may increase his
speed
B) his weight may be
reduced
C) necessary centripetal
force may be available from
the horizontal component of
the normal reaction due to
the track to maintain the
curved motion.
D) no frictional force
may be produced between
the wheels and the axle
Answer: C) necessary centripetal force may be available from the horizontal
component of the normal reaction due to the track to maintain the curved motion.
Explanation:
No circular or curved motion is possible without providing the necessary
centripetal force. (C) provides this and so is the answer.
92) Which Color has the Longest Wavelength?
A) Violet B) Yellow
C) Red D) White
Answer: C) Red
Explanation:
The visible colors from Longest wavelength to Shortest wavelength are :: Red,
Orange, Yellow, Green, Blue and Violet.

34. Red > Orange > Yellow > Green > Blue > Violet.
1. Infrared radiation has a longer wavelength than visible Red light.
2. Ultraviolet radiation has a shorter wavelength than the visible violet light.
3. The white light is a mixture of the colors of the visible spectrum.
93) Reading of a barometer going down is an indication of
A) Storm B) Rainfall
C) Snow D) Intense heat
Answer: B) Rainfall
Explanation:
Barometer is instrument which is used to measure to pressure. A slow downfall of
reading suggests a low pressure area is passing in a nearby region, it may rains. If
the reading is going down very fast then its an indication of storm (within 5-6
hours).
94) An atom bomb based upon the principal of ________
A) Nuclear fission B) Nuclear fussion
C) Controlled chain
reaction
D) None of these
Answer: A) Nuclear fission
95) Which of the following physical quantities have the same dimensions
A) momentum and
impulse
B) power and young
modulus

35. C) Energy and angular
Momentum
D) force constant and
moment of inertia
Answer: A) momentum and impulse
96) Which law is also called law of inertia ?
A) Newton first law B) Newton second law
C) Newton third law D) All of above
Answer: A) Newton first law
97) Which component of an IED creates an electrical charge?
A) activator B) fuse
C) explosive D) power source
Answer: D) power source
Explanation:
The power source such as a Battery of an IED creates an electrical charge.
What are IED's ::
An Improvised Explosive Device (IED) is a bomb constructed and deployed in
ways other than in conventional military action. It may be constructed of
conventional military explosives, such as an artillery shell, attached to a detonating
mechanism. IEDs are commonly used as roadside bombs.
98) Curie is the unit of
A) temparature B) radio activity

36. C) heat D) energy
Answer: B) radio activity
99) Number of basic SI unit is
A) 4 B) 7
C) 6 D) 5
Answer: B) 7
100) Distance of stars are measured in
A) Galactic unit B) seller mile
C) Cosmic Kilometre D) Light year
Answer: D) Light year