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# JIPMER Physics Mock Test - 3

## 60 Questions MCQ Test JIPMER 2020: Subject wise and Full Length Mock Tests | JIPMER Physics Mock Test - 3

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This mock test of JIPMER Physics Mock Test - 3 for NEET helps you for every NEET entrance exam. This contains 60 Multiple Choice Questions for NEET JIPMER Physics Mock Test - 3 (mcq) to study with solutions a complete question bank. The solved questions answers in this JIPMER Physics Mock Test - 3 quiz give you a good mix of easy questions and tough questions. NEET students definitely take this JIPMER Physics Mock Test - 3 exercise for a better result in the exam. You can find other JIPMER Physics Mock Test - 3 extra questions, long questions & short questions for NEET on EduRev as well by searching above.
QUESTION: 1

Solution:
QUESTION: 2

Solution:
QUESTION: 3

### When a resistance of 2 ohm is connected across the terminals of a cell, the current is 0.5 A. When the resistance is increased to 5 ohm, the current is 0.25 A. The e.m.f. of the cell is

Solution:
QUESTION: 4

Increasing the charge on the plates of a capacitor means

Solution:

C is fixed for a given capacitor.
Charge Q increases the potential V as V = Q/C

QUESTION: 5

The inductance of a coil is L = 10 H and resistance R = 5 Ω . If applied voltage of battery is 10 V and it switches off in 1 millisecond, find induced emf of inductor.

Solution:
QUESTION: 6

When a 12 Ω resistor is connected with a moving coil galvanometer then its deflection reduces from 50 divisions to 10 divisions. The resistance of the galvanometer is

Solution:
QUESTION: 7

Racitor eactance of a capof capacitance CμF for a.c. of frequency 400/π Hz is 25 Ω. The value of C is

Solution:
QUESTION: 8

A particle is moving on the inside of a smooth sphere of radius a, describes a horizontal circle at a distance a 2 below the centre of the sphere. Its speed is then-

Solution:

Here OM = a 2, OP = a
∴ cos θ = a 2 a = 1 2
⇒ θ = 60 �
R cos θ = m g
R sin θ = mv 2 PM
∴ tan θ = v 2 PM.g
v2 = PM . g tan θ
= g.a sin 60� .tan 60�
= ga 32.3
=  2 ag
v = 126 ag

QUESTION: 9

Two electric charge 12 μC and −6 μC are places 20 cm apart in air. There will be a point P at which electric potential is zero on the line joining these two charges and outside, excluding the region between them. The distance of P from −6 μC charge is

Solution:
QUESTION: 10

Which of the following electromagnetic waves have the smallest wavelength?

Solution:
QUESTION: 11

A conducting sphere of radius 10 cm is charged with 10 μC. Another uncharged sphere of radius 20 cm in allowed to touch it for some time. If both the spheres are separated, then surface density of charges on the spheres will be in the ratio of

Solution:
When the two conducting spheres touch each other there will be a flow of charge until they both have the same potential.
Let R1 and R2 be the radii of spheres 1 and 2, respectively.  Let Q1 and Q2 be the charges on spheres 1 and 2, respectively, after they are separated. Since both have the same potential,

V = Q1/C1 = Q2/C2
⇒ Q1/(4πϵ0R1) = Q2/(4πϵ0R2)
⇒ Q1/R1 = Q2/R2
⇒  Q1/Q2 = R1/R2
Surface charge density on sphere 1 = σ1 =  Q1/(4πR12)
Surface charge density on sphere 2 = σ2 = Q2/(4πR22)

σ1 /σ2 = (Q1/Q2) x (R22/R12)
=  (R1/R2) x (R22/R12)
= R2/R1
= 20 cm/10 cm
= 2
Therefore   σ1 : σ2 = 2 : 1

QUESTION: 12

A block of mass 10kg is pushed by a force F on a horizontal rough plane moves with an acceleration 5 ms-2 When force is doubled, its aceleration becomes 18 ms-2 . The coefficient of friction is (g = 10 ms-2  ).

Solution:
QUESTION: 13

If acceleration due to gravity on the earth's surface is g, then value of acceleration due to gravity at a height of 32 km above the earth's surface is

Solution:
QUESTION: 14

A body of mass m is taken to the bottom of a deep mine. Then

Solution: Because the body taken up against gravitation accelaration.
QUESTION: 15

The root mean square speed of hydrogen molecules at 300 K is 1930 m/s. Then the root mean square speed of oxygen molecules at 900 K will be

Solution:
QUESTION: 16

The temperature of a body falls from 50oC to 40oC in 10 minutes. If the temperature of the surroundings is 20oC Then temperature of the body after another 10 minutes will be

Solution:
QUESTION: 17

A monochromatic beam of light is used for the formation of fringes on the screen by illuminating two slits in the Young's double-slit interference experiment. When a thin film of mica is interposed in the path of one of the interfering beams, then

Solution:

Interposing mica does not affect the fringe width but shifts the fringe pattern

QUESTION: 18

The magnetic induction at the centre of a current carrying circular coil of radius 10cm is 5√5 times the magnetic induction at a point on its axis. The distance of the point from the centre of the coil in cm is

Solution:
QUESTION: 19

An electron (charge q coulomb) enters a magnetic field of H weber/m2 with a velocity of ν m/s in the direction as that of the field. The force on the electron is

Solution:
QUESTION: 20

There are three voltmeters of the same range but of resistance 10000 Ω, 8000 Ω and 4000 Ω respectively. The best voltmeter among these is the one whose resistance is

Solution:
QUESTION: 21

Isogonic lines on magnetic map represent the lines of

Solution:
QUESTION: 22

The magnetic needle of a vibration magnetometer makes 12 oscillations per minute in the horizontal component of earth's magnetic field. When an external short bar magnet is placed at some distance along the axis of the needle in the same line, it makes 15 oscillations per minute. If the poles of the bar magnet are interchanged, the number of oscillations it makes per minute is

Solution:

The frequency of a vibration magnetometer is If an external magnet is placed near the magnet along the axis If the poles of the magnet are reversed Dividing (1) and (2) QUESTION: 23

The couple acting on a magnet of length 10cm placed in a uniform magnetic field of intensity 40N/wb such that the axis of the magnet makes 45o with the field direction is 2 ∕ 10 Nm. The pole strength of the magnet in webers

Solution:
QUESTION: 24

Two mercury drops with radii in the ratio of 3 : 4 fall from a great height through the viscous liquid. The ratio of their terminal velocities is

Solution:
QUESTION: 25

In a liquid flowing through a pipe, the pressure difference between its ends is made half and radius is doubled. If the initial rate of flow of liquid was Q, then new rate of flow of liquid through the pipe is

Solution:
QUESTION: 26

A wire of length L and cross-section A is made of material of Young's modulus Y. If it is stretched by an amount x, then work done is

Solution:
QUESTION: 27

Two discs of same thickness but of different radii are made of two different materials such that their masses are same. The densities of the materials are in the ratio 1:3. The moments of inertia of these discs about the respective axes passing through their centres and perpendicular to their planes will be in the ratio

Solution:
QUESTION: 28

From the top of a tower, a particle is thrown vertically downwards with a velocity of 10 m/s. The ratio of the distances, covered by it in the 3rd and 2nd seconds of the motion is (Take g=10m/s2)

Solution:
QUESTION: 29

A body weighs 8 gm when placed in one pan and 18 gm when placed on the other pan of a false balance. If the beam is horizontal when both the pans are empty, the true weight of the body is

Solution:

If the beam is horizontal, the apparent weight  QUESTION: 30

The material used to slow down neutrons in a reactor is called

Solution:
QUESTION: 31

In a fission of U235 nucleus on average ----- neutrons are released.

Solution:

When U235 is bombarded by a neutron, it splits into barium,
Krypton and 2 or 3, so average 2.5 neutrons per fission

QUESTION: 32

A mass attached to a spring oscillates every 2 s. If the mass is increased by 2 kg, then time period increases by 1 s. The initial mass is

Solution:
QUESTION: 33

The objective of a compound microscope is essentially

Solution:
QUESTION: 34

Photons of energy 5.5 eV fall on the surface of the metal emitting photoelectrons of maximum kinetic energy 4.0 eV. The stopping voltage required for these electrons are

Solution:
QUESTION: 35

Work function of a metal is 2.1 eV. Which of the waves of the following wavelengths will be able to emit photoelectrons from its surface

Solution:
QUESTION: 36

The horizontal range of a projectile is 4√3 times the maximum height achieved by it, then the angle of projection is

Solution:
QUESTION: 37

A converging crown glass lens has a focal length 20 cm for the violet rays. Its focal length for red rays is (given μ= 1.53 and μr = 1.56 )

Solution:
QUESTION: 38

The objective of an astronomical telescope has a large aperture to

Solution:
QUESTION: 39

One face of the glass prism is silver polished. A light ray falls at an angle of 45o on the other face. After reflection it is subsequently reflected from the silvered face and then retraces its path. The refracting angle of the prism is 30o . The refractive index of the prism is

Solution:

Angle of incidence (i) = 45o
r1 + r2 = A = 30o
μ = sin i sin r [From Snell's law]
When the ray of light retraces its path at the silvered face, the angle of refraction becomes 30o
μ = sin i/sin r = √2

QUESTION: 40

A lens is behaving as convex lens in air and concave in water, then its refractive index is

Solution:
QUESTION: 41

A thin uniform rod AB of mass m and length L is hinged at one end A to the level floor. Initially it stands vertically and is allowed to fall freely to the floor in the vertical plane. The angular velocity of the rod, when its end B strikes the floor is

Solution:

Since the centre of gravity of the rod is at its centre,
the loss in PE when its end B strikes the floor = mg ( L/2 ) = 1/2 mg L
Gain in KE = 1/2 Iω2
where I is the moment of intertia of the rod about an axis passing through its end and perpendicular to its length
which is given by I = 1/3 mL2
Now gain in KE = loss in PE. i.e.
1/2 x 1/3 mL2 x ω2 = 1/2 mgL
which gives ω = √3g/L

QUESTION: 42

The maximum velocity of a particle executing simple harmonic is V. If the amplitude is doubled and the time period of oscillation decreased to 1/3 of its original value, the maximum velocity becomes

Solution:
QUESTION: 43

A body executes S.H.M. of period 3 s under the influence of one force, and S.H.M. of period 4 s under the influence of a second force. when both the forces act simultaneously in the same direction, the period of oscillation will be

Solution:
QUESTION: 44

When a semiconductor is continuously heated the value of its resistance

Solution:
QUESTION: 45

In p-type semiconductor the majority charge carriers are

Solution:
QUESTION: 46

The equation of a progressive wave is y = 0.002 sin2π (2t − 0.01 x) , its wave length λ is

Solution:
QUESTION: 47

When the capillary tube is lowered into water, the mass of water raised in the tube, above the outside water level is 5gm. If the radius of the tube is doubled, the mass of water that rises in the capillary tube above the outside water level is

Solution:
QUESTION: 48

A 220 volt and 800 watt electric kettle and three 220 volt and 100 watt bulbs are connected in parallel. On connecting this combination with 220 volt electric supply, the total current will be

Solution:
QUESTION: 49

Antimony and B is muth are usually used in a thermocouple, because

Solution:
QUESTION: 50

At 25oC, length of a metal rod is 10m and its cross-section is 50sq.cm. Calculate the temperature at which it can have the same length as the length obtained by a longitudinal force of 4 x 104N . α = 12 x 10-6oC ; Y = 2 x 1011 Nm-2

Solution:
QUESTION: 51

A mono atomic gas is supplied the heat Q very slowly keeping the pressure constant. The work done by the gas will be

Solution:
QUESTION: 52

When a current is passed through a junction of two dissimilar metals, heat is evolved or absorbed at the junction. This process is called

Solution:
QUESTION: 53

If the ratio of specific heat of a gas at constant pressure to that at constant volume is γ, the change in internal energy of a mass of gas, when the volume changes from V to 2V at constant pressure p, is

Solution:
QUESTION: 54

Which one of the following does not have the same dimensions

Solution:
QUESTION: 55

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

Solution:
QUESTION: 56

A wave front travels

Solution:
QUESTION: 57

In Young's double slit experiment, two slits are made 5 mm apart and the screen is placed 2 m away. What is the fringe separation when light of wavelength 500 nm is used?

Solution:
QUESTION: 58

A cylindrical tube open at both ends, has a fundamental frequency f in air. The tube is dipped vertically in water so that half of it is in water. The fundamental frequency of air column is now

Solution:
QUESTION: 59

Two waves are approaching each other with a velocity of 16 m/s and frequency n. The distance between two consecutive nodes is

Solution:
QUESTION: 60

The kinetic energy of a body becomes 4 times its initial value. The new linear momentum will be

Solution:

KE = P2/2m
When KE becomes 4 times, p2 is 4 times or p becomes 2 times