Sample AFMC Physics Mock Test


50 Questions MCQ Test AFMC Mock Test Series 2020 | Sample AFMC Physics Mock Test


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This mock test of Sample AFMC Physics Mock Test for NEET helps you for every NEET entrance exam. This contains 50 Multiple Choice Questions for NEET Sample AFMC Physics Mock Test (mcq) to study with solutions a complete question bank. The solved questions answers in this Sample AFMC Physics Mock Test quiz give you a good mix of easy questions and tough questions. NEET students definitely take this Sample AFMC Physics Mock Test exercise for a better result in the exam. You can find other Sample AFMC Physics Mock Test extra questions, long questions & short questions for NEET on EduRev as well by searching above.
QUESTION: 1

Best neutron moderator is

Solution: Its heavy water becz. Weight of heavy water is more.
QUESTION: 2

Mass defect of an atom refers to

Solution: A mass defect refers to the difference in mass between of an atom and the sum of the masses of the protons, neutrons, and electrons of the atom. ... The "missing" mass is the energy released by the formation of the atomic nucleus.
QUESTION: 3

Who indirectly determined the mass of the electron by measuring the charge of the electron ?

Solution:
QUESTION: 4

Resistance of a wire at 20°C is 20 Ω and at 500°C is 60 Ω. At what temperature its resistance is 25 Ω ?

Solution:
QUESTION: 5

Photo cell is a device to

Solution: Photo cell is used to convert photon energy(I.e. light energy) into chemical energy....
QUESTION: 6

A nichrome wire 50cm long and square millimeter cross-section carries a current of 4A when connected to a 2V battery. The resistivity of nichrome wire in ohm meter is

Solution:

QUESTION: 7

Two coils are placed close to eachother. The mutual inductance of the pair of coils depends upon

Solution: Two coils are placed close to each other. Themutual inductance of the pair of coils depends upon. Two coils are placed close to each other. The mutual inductance of the pair of coils depends upon relative position and orientation of the two coils.
QUESTION: 8

The p.d. across an instrument in an A.C. circuit of frequency f is V and the current flowing through it is I such that V = 5 cos 2π amp. The power dissipated in the instrument is

Solution:

 Answer :- a

Solution :- V = 5cos2πft    [ω = 2πf]

V = 5cosωt

=5sin(ωt+π2)  and i = 2sinωt

Power = Vrms×irms×cosφ=0

(Since φ = π/2, therefore cosφ = cos(π/2)=0)

QUESTION: 9

The current flowing in a coil of self inductance 0.4 mH is increased by 250 mA in 0.1 s. The e.m.f. induced will be

Solution:

As current is increasing, induced e.m.f. is in opposite direction, therefore, e = - 1 mV.

QUESTION: 10

The electrostatic capacitance depends on

Solution:


The capacitance is proportional to the surface area of the conducting plate and inversely proportional to the distance between the plates. Hence, it depends upon the size of the conductor, and not upon the nature of conductor, thickness or colour.

QUESTION: 11

The capacity of a condenser with two identical plates separated by a distance 'd' in air is 'C'. If the distance of separation is reduced to d/2, the capacity is

Solution:
QUESTION: 12

If size of the earth is reduced to half, then no. of days in one year will be

Solution: Correct answer is 'C' because time period is not depend on radius.
QUESTION: 13

Figure shows two large cylindrical shells having uniform linear charge densities + λ and - λ . Radius of inner aylinder is 'a' and that of outer cylinder is 'b'. A charged particle of mass m , charge q revolves in a circle of radius r. Then its speed 'V' is:
[Neglect gravity and assume the radii of both cylinders to be very small in comparison to their length]

Solution:
QUESTION: 14

The energy emitted per second by a black body at 27°C is 10 J. If the temperature of the black body is increased to 327°C, the energy emitted per second will be

Solution:
QUESTION: 15

Vapour is injected at a uniform rate in a closed vessel which was initially evacuated. The pressure in the vessel

Solution:
QUESTION: 16

At what temperature, the root mean square velocity of a hydrogen molecules is equal to that of an oxygen molecules at 47°C?

Solution:
QUESTION: 17

The diameter of a copper sphere is 6 cm. It is melted to form a wire of uniform cross-section. If the length of the wire is 36 cm then find the radius of the wire.

Solution:
QUESTION: 18

If a long hollow copper pipe carries a current, the produced magnetic field will be

Solution: If the current flows on the surface of a long hollow copper pipe. Then the magnetic field inside is zero. Hence, there shall be magnetic field produced outside the pipe.
QUESTION: 19

A ball of mass m strikes elastically a wall at an angle of 30° with velocity ν. The change in momentum is

Solution: Change in momentum (P)=2mv cos theta. P=2mv cos 30. P=2mv√3/2. P=√3mv....
QUESTION: 20

In a surface tension experiment with a capillary tube, water rises upto 8 mm. If the same experiment is repeated on an artificial satellite, which is revoling around the earth, water will tise in capillary tube upto a height of

Solution: Height of capillary rise liquid is given by h = 2T/(rρg) . T is surface tension, r is radius of capillary tube, ρ is density and g is acceleration due to gravity.Since acceleration due to gravity is in denominator and acceleration due to gravity is negligibly small at the orbit where satteleite is revolving around the earth, capillary rise will be very high. So 'full length' may be the correct answer.
QUESTION: 21

Two solid pieces, one of steel and the other of aluminium when immersed completely in water have equal weights. When the solid pieces are weighed in air

Solution:

Apparent weight in air

QUESTION: 22

If pressure inside two soap bubbles are 1.01 and 1.02 atm respectively, then the ratio between their volumes is (Take atmospheric pressure = 1 atm)

Solution:
QUESTION: 23

An incompressible fluid flows steadily through a cylindrical pipe which has radius 2 R at point A and radius R at point B. If velocity at point A is ν, then its velocity at point B is

Solution:
ATQ, equation of continuity,
Area is inversely proportional to flow rate, 
therefore if area is reduced by four times 
the flow rate becomes 4 times =4v
QUESTION: 24

The potential energy of a molecule on the surface of a liquid compared to one inside the liquid is

Solution:
QUESTION: 25

Water level rises in a capilary tube, if the angle of contact is

Solution: If the angle of contact is less than 90 ,then the level of water rises in concave meniscus.
QUESTION: 26

Which of the following affets the elasticity of a substance?

Solution:
QUESTION: 27

A wire can be broken by applying a load of 200 N.The force required to break another wire of the same length and same material, but double in diameter, is

Solution:

We know that, E = -dΦ/dt,...

E = -d/dt {2t² - 3t + 1}
= -(4t - 3)
at t = 0.25 sec,...
E = -(4×0.25 - 3) = 2 V

QUESTION: 28

A body starts from rest. What is the ratio of the distance travelled by the body during the 4th and 3rd second

Solution:

QUESTION: 29

For a projectile, the ratio of maximum height reached to the square of flight time is (g = 10 ms⁻2)

Solution: Hmax=u^2/2g. Tmax=2u/g.. given in question square of time of flight=( 2u/g)^2=4u^2/g^2... Hmax/Tmax=u^2/2×10/4u^2/10^2... =10^2/2×10×4.=100/80=5/4..
QUESTION: 30

To increase the magnification of a telescope

Solution:
QUESTION: 31

The potential energy of a particle executing simple harmonic motion at a distance y from its equilibrium position is

Solution:
QUESTION: 32

The frequency of a light wave in a material is 2 x 1014 H z and wavelength is 5000 Å. The refractive index of material will be

Solution:
QUESTION: 33

When a sphere of moment of inertia I about an axis through its centre of gravity and mass m rolls down from rest, on an inclined plane without slipping, its kinetic energy is

Solution: Rolling motion=Pure translatory motion + Pure rotatory motion.So option D is correct.
QUESTION: 34

Time of exposure for a photographic print is 10 second, when a lamp of 50 Cd is placed at 1 m from it. Then another lamp of luminous intensity I is used, and is kept at 2 m from it. If the time of exposure now is 20 s, the value of I in (in Cd) is :

Solution:
QUESTION: 35

When light travels from one medium to another which are separated by a sharp boundary, the characteristic of light which does not change, is

Solution: It is the frequency of the light that doesn't change. This I can justify with the help of Planck's formula, E=hf, where ‘E’ is the Energy of one light quantum (one photon), ‘h’ is the Planck's constant and ‘f ’ is the frequency. Because a photon can't be split into pieces, its energy stays constant and so does the frequency of the beam. Frequency of light does not ever change, as long as you can be sure that the photons are the same as the photons at the beginning. Putting mathematically, since speed of light and its wavelength are not absolute quantities and vary from medium to medium, their ratio changes in such a way that the frequency stays constant!
QUESTION: 36

A wheel is rotating at 900 r.p.m. about its axis When power is cut off it comes to rest in 1 minute The angular retardation in rad/s2 is

Solution: W=900x2π÷60 w=30π on applying w'-w=-át 0-30π=-á x 60 -á=π/2
QUESTION: 37

A body is rotating with angular velocity 30 rad/s. If its kinetic energy is 360 J, then its moment of inertia is

Solution: Kinetic energy = moment of inertia (I) multiply square of angular velocity (w) and divide by 2 and then put given value then you get answer.
QUESTION: 38

A ballet dancer of moment of inertia I is spinning about the vertical axis with an angular velocity of 20 rad-s⁻1. If she suddenly changes her angular velocity to 10 rad-s⁻1, then new moment of inertia would be

Solution: I1w1=I2w2
I1×20=I2×10
I1×20/10=I2
2I1=I2
QUESTION: 39

A fan is making 600 rev-min⁻1. If it makes 1200 rev-m⁻1, then increase in its angular velocity is

Solution: Increase in its angular velocity, w=w2-w1. w=2πn2-2πn1. w=2π(n2-n1). here,n1=600rev/min=600rev/60 sec. n2=1200rev/min=1200rev/60sec. w=2π(1200/60-600/60). w=2π(20-10). w=2π(10). w=20π...
QUESTION: 40

The period of spring oscillating simple harmonically

Solution:
QUESTION: 41

A p-type semiconductor is

Solution: Any type of semiconductor either p or n type both are neutral i.e. uncharged.
QUESTION: 42

At 27°C a gas is suddenly compressed such that its pressure becomes 1/8th of original pressure. Temperature of the gas will be (γ = 5/3)

Solution:
QUESTION: 43

The length and breath of a metal sheet are 3.124 m and 3.002 m respectively. The area of this sheet up to four significant figures is

Solution:
QUESTION: 44

SI unit of pressure is

Solution:
QUESTION: 45

A suitable unit for gravitational constant is

Solution: F= G m1 m2 /r^2. Newton=G kg kg /m^2. F=Newton m^2/kg^2. F=Newton m^2 kg^-2.....
QUESTION: 46

If the two slits in Young's experiment have width ratio 1:4, the ratio of intensity at maxima and minima in the interference pattern in

Solution:


QUESTION: 47

When a source is linear, the wavefront is

Solution:
QUESTION: 48

According to wave theory, light is a form of energy which travels through a medium in the form of

Solution:
QUESTION: 49

Standing waves are produced in a 10 m long stretched string. If the string vibrates in 5 segments and the wave velocity is 20 m/s, the frequency is

Solution:
QUESTION: 50

An isolated particle of mass m is moving in a horizontal plane along the x-axis at a certain height above the ground. It suddenly explodes into two fragments of masses m/4 and 3m/4. An instant later, the smaller fragment is at y = 15 cm. The larger fragment at this instant is at

Solution:

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