R4RIN – MCQs, Mock Tests | NCERT Class 11 MCQ Questions for Class 11 Physics sets 2

A block of mass M is placed on a flat surface. A force is applied to move it parallel to the surface. The frictional force f developed is proportional to the

1. square of the mass of the body
2. mass of the body
3. reciprocal of the mass of the body
4. reciprocal of the square of the body

✅ Correct Answer: 2

A man of 60 kg weight is standing at rest on a platform. He jumps up vertically a distance of 1 m and the platform at the same instant moves horizontally forward with the result that the man lands 1 meter behind the point on the platfrom from where the took the jump the total work done by the man at the instant he lands is

1. 300 J
2. 150 J
3. 600 J
4. zero

✅ Correct Answer: 3

A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?

1. 7.2 J
2. 3.6 J
3. 120 J
4. 1200 J

✅ Correct Answer: 2

A body of mass 10 kg is travelling with uniform speed of 5 m/s. Its kinetic energy is

1. 25 J
2. 125 J
3. 1250 J
4. 1000 J

✅ Correct Answer: 2

A ball is dropped from a height of 1 m. If the coeffcient of restitution between the surface and ball is 0.6, the ball rebounds to a height of

1. 0.6 m
2. 0.4 m
3. 1 m
4. 0.36 m

✅ Correct Answer: 4

A quantity of work of 1000 J is done in 2 seconds. The power utilised is

1. 998 W
2. 1002 W
3. 2000 W
4. 500 W

✅ Correct Answer: 4

When the linear momentum of a particle is increased by 1% its kinetic energy increases by x%. When the kinetic energy of the particle is increased by 300%, its linear momentum increases by y%. The ratio of y to x is

1. 300
2. 150
3. 100
4. 50

✅ Correct Answer: 4

A solid cylinder of length 1 m and diameter of cross section y 100 cms is first placed with its axis vertical its then slowly inclined till its axis is horizontal. The loss in its potential energy if the mass of the cylinder is 10 kg is

1. 5g J
2. 10g J
3. Zero
4. g J

✅ Correct Answer: 3

A body of mass 10 kg moving at a height of 2 m, with uniform speed of 2 m/s. Its total energy is

1. 316 J
2. 216 J
3. 116 J
4. 392 J

✅ Correct Answer: 2

Two masses 1 g and 4 g are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is

1. 4 : 1
2. 1 : 2
3. 0 : 1
4. 1 : 6

✅ Correct Answer: 2

A body of mass 10 kg is initially at a height of 20 m above the ground. It falls to a height of 5 m above the ground. Its potential energy in the new position is

1. 490 J
2. 50 J
3. 100 J
4. 300 J

✅ Correct Answer: 1

A marble moving with some velocity collides perfectly elastically head-on with another marble at rest having mass 1.5 times the mass of the colliding marble. The percentage of kinetic energy by the colliding marble after the collision is

1. 4
2. 25
3. 44
4. 67

✅ Correct Answer: 1

A body of mass 100 kg falls from a height of 10 m. Its increase in kinetic energy is

1. 9800 J
2. 1000 J
3. 5000 J
4. 3000 J

✅ Correct Answer: 1

An isolated particle of mass m is moving in a horizontal plane (x-y), 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

1. y = -5 cm
2. y = +20 cm
3. y = +5 cm
4. y = -20 cm

✅ Correct Answer: 1

A body of mass 20 kg is initially at a height of 3 m above the ground. It is lifted to a height of 2 m from that position. Its increase in potential energy is

1. 100 J
2. 392 J
3. 60 J
4. -100 J

✅ Correct Answer: 2

A body of mass 10 kg is moved parallel to the ground, through a distance of 2 m. The work done against gravitational force is

1. 196 J
2. -196 J
3. 20 J
4. zero

✅ Correct Answer: 4

An electric heater of rating 1000 W is used for 5 hrs per day for 20 days. The electrical energy utilised is

1. 150 kWh
2. 200 kWh
3. 100 kWh
4. 300 kWh

✅ Correct Answer: 3

A body of M.I. 3 kg m² rotating with an angular velocity 2 rad/s has the same K.E. as a mass of 12 kg moving with a velocity of

1. 1 m/s
2. 2 m/s
3. 4 m/s
4. 8 m/s

✅ Correct Answer: 1

A particle performing uniform circular motion has angular momentum L. If its angular frequency is doubled and its kinetic energy halved, then the new angular momentum is

1. L/2
2. L/4
3. 2 L
4. 4 L

✅ Correct Answer: 2

A thin uniform, circular ring is rolling down an inclined plane of inclination 300 without slipping. Its linear acceleration along the inclined plane will be

1. g/2
2. g/3
3. g/4
4. 2g/3

✅ Correct Answer: 1

Moment of inertia depends on

1. Distribution of particles
2. Mass
3. Position of axis of rotation
4. All of these

✅ Correct Answer: 4

Calculate the M.I. of a thin uniform ring about an axis tangent to the ring and in a plane of the ring, if its M.I. about an axis passing through the centre and perpendicular to plane is 4 kg m².

1. 12 kg m²
2. 3 kg m²
3. 6 kg m²
4. 9 kg m²

✅ Correct Answer: 3

If a body is rotating about an axis, passing through its centre of mass then its angular momentum is directed along its

1. Radius
2. Tangent
3. Circumference
4. Axis of rotation

✅ Correct Answer: 4

A solid cylinder of mass 20 kg, has length 1 metre and radius 0.5m. then its momentum of inertia in kg m² about its geometrical axis is

1. 2.5
2. 5
3. 1.5
4. 3

✅ Correct Answer: 1

A particle moves on a circular path with decreasing speed. Choose the correct statement.

1. Angular momentum remains constant.
2. Acceleration is towards the centre
3. Particle moves on a spiral path with decreasing radius
4. The direction of angular momentum remains constant.

✅ Correct Answer: 4

The M.I. of uniform circular disc about a diameter is I. its M.I. about an axis perpendicular to its plane passing through a point on its rim will be

1. 4 I
2. 6 I
3. 8 I
4. 9 I

✅ Correct Answer: 2

Which is the wrong relation from the following?

1. t = I a
2. F = ma
3. L = I w
4. I = t a

✅ Correct Answer: 4

A solid sphere is rotating in free space. If the radius of the sphere is increased keeping mass same, which one of the following will not be affected?

1. Moment of inertia
2. Angular momentum
3. Angular velocity
4. Rotational kinetic energy

✅ Correct Answer: 2

A hollow cylinder and a solid cylinder having different mass diameter are released from rest simultaneously from the of an inclined plane. Which will reach the bottom first?

1. solid cylinder
2. cant be determined without knowing their masses
3. hollow cylinder
4. cant be determined without knowing their diameters

✅ Correct Answer: 1

If I, a and t are the moment of inertia, angular acceleration and torque respectively of a body rotating about any axis with angular velocity w, then

1. t = Ia
2. t = Iw
3. I = tw
4. a = Iw

✅ Correct Answer: 1

A dancer on ice spins faster when she folds here arms. This is due to

1. Increases in energy and increase in angular momentum
2. Decrease in friction at the skates
3. Constant angular momentum and increase in kinetic energy
4. Increase in energy an decreases in angular momentum

✅ Correct Answer: 3

The moment of inertia of a uniform semicircular disc of mass M and radius about a line perpendicular to the plane of the disc through the centre is

1. (2/5) Mr²
2. (1/4) Mr power 2
3. (1/2) Mr²
4. Mr²

✅ Correct Answer: 3

A particle moves for 20 s with velocity 3 m/s and then moves with velocity 4 m/s for another 20 s and finally moves with velocity 5 m/s for next 20 s. what is the average velocity of the particle?

1. 3 m/s
2. 4 m/s
3. 5 m/s
4. Zero

✅ Correct Answer: 2

For increasing the angular velocity of an object by 10%, the kinetic energy has to be increased by

1. 40%
2. 20%
3. 10%
4. 21%

✅ Correct Answer: 3

The radius of the earth is 6400 km and g = 10 m/s². In order that a body of 5 kg weighs zero at the equator, the angular speed of the earth is

1. 1/80 rad /s
2. 1/400 rad /s
3. 1/800 rad /s
4. 1/1600 rad /s

✅ Correct Answer: 3

A body weighs 500 N on the surface of the earth. How much would it weight half way below the surface of the earth?

1. 1000 N
2. 500 N
3. 250 N
4. 125 N

✅ Correct Answer: 3

The time – period of a satellite of earth is 5 hours. If the separation between the earth and the satellite is increased to 4 times the previous value, the new time – period will become

1. 10 hours
2. 20 hours
3. 40 hours
4. 80 hours

✅ Correct Answer: 3

A missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is

1. Positive
2. Negative
3. Zero
4. may be positive or negative

✅ Correct Answer: 2

What would be the duration of the year if the distance between the earth and the sun gets doubled?

1. 1032 days
2. 129 days
3. 365 days
4. 730 days

✅ Correct Answer: 1

If a body of mass m is taken out from a point below the surface of earth equal to half the radius of earth, R, to a height R above the earths surface, then work done on it will be

1. (5/6) mgR
2. (6/7) mgR
3. (7/8) mgR
4. (8/9) mgR

✅ Correct Answer: 3

A artificial satellite moving in a circular orbit around the earth has a total (kinetic + potential) energy E0. Its potential energy is

1. 2E0
2. E0
3. 1.5 E0
4. -E0

✅ Correct Answer: 1

A body is projected vertically from the surface of the earth of radius R with velocity equal to half of the escape velocity. The maximum height reached by the body is

1. R
2. R/2
3. R/3
4. R/4

✅ Correct Answer: 3

The escape velocity for a body projected vertically upwards from the surface of the earth is 11 km/s. If the body is projected at an angle of 450 with the vertical, the escape velocity will be

1. 11/√2 km/s
2. 11√2 km/s
3. 2 km/s
4. 11 km/s

✅ Correct Answer: 4

There is no atmosphere on the moon because

1. it is closer to the earth
2. it revolves round the earth
3. it gets light from the sun
4. the escape velocity of gas molecules is less than their root mean square velocity here

✅ Correct Answer: 4

The value of g at a particular point is 9.8 m/sec² suppose the earth suddenly shrink uniformly to half its present size without losing any mass. The value of g at the same point (assuming that the distance of the point from the centre of the earth does not shrink) will become

1. 9.8 m/sec²
2. 4.9 m/sec²
3. 19.6 m/sec²
4. 2.45 m/sec²

✅ Correct Answer: 1

If the radius of the earth were to be raise by 1% its mass remaining the same, the acceleration due to gravity on the surface of the earth will

1. increase by 1%
2. decrease by 2%
3. decrease by 1%
4. increase by 2%

✅ Correct Answer: 4

The escape velocity of projection from the earth is approximately (R = 6400 km)

1. 7 km/sec
2. 112 km/sec
3. 12.2 km/sec
4. 1.1 km/sec

✅ Correct Answer: 3

Who among the following first gave the experimental velocity of G?

1. Cavendish
2. Copernicus
3. Brook Taylor
4. None of these

✅ Correct Answer: 1

A satellite S is move in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth .

1. The acceleration of S is always directed towards the centre of the earth.
2. The total mechanical energy of S varies periodically with time.
3. The angular momentum of S about the centre of the earth changes in direction, but its magnitude remains constant.
4. The linear momentum of S remains constant in magnitude.

✅ Correct Answer: 1

The mean radius of the earth is R, its angular speed on its own axis is w and the acceleration due to gravity at earths surface is g. The cube of the radius of the orbit of a geo-stationary satellite will be

1. r²g / w
2. R²w²/ g
3. RG w²
4. R²g / w²

✅ Correct Answer: 3

If the distance between the earth and the sun were half its present value, the number of day in a year would have been

1. 64.5
2. 129
3. 182.5
4. 730

✅ Correct Answer: 2

The masses of two planets are in the ratio 1 : 2. Their radii are in the ratio 1 : 2. The acceleration due to gravity on the planets are in the ratio.

1. 1 : 2
2. 2 : 1
3. 3 : 5
4. 5 : 3

✅ Correct Answer: 1

A body of mass 1 kg is attached to one end of a wire and rotated in horizontal circle of diameter 40 cm with a constant speed of 2 m/s. what is the area of cross-section of the wire if the stress developed in the wire is 5 × 106 N/m²?

1. 2 mm²
2. 3 mm²
3. 4 mm²
4. 5 mm²

✅ Correct Answer: 3

In a wire, when elongation is 2 cm energy stored is E. if it is stretched by 10 cm, then the energy stored will be

1. E
2. 2 E
3. 4 E
4. 25 E

✅ Correct Answer: 4

Two wires A and B are of the same length. The diameters are in the ratio 1 : 2 and the Youngs modulus are in ratio 2 : 1. if they are pulled by the same force, then their elongations will be in ratio

1. 4 : 1
2. 1 : 4
3. 1 : 2
4. 2 : 1

✅ Correct Answer: 4

Hookes law essentially defines

1. Stress
2. Strain
3. Yield point
4. Elastic limit

✅ Correct Answer: 4

Longitudinal strain is possible in the case of

1. Gases
2. Liquid
3. Only solids
4. Only gases & liquids

✅ Correct Answer: 3

Two wires have the same material and length, but their masses are in the ration of 4 : 3. If they are stretched by the same force, their elongations will be in the ratio of

1. 2 : 3
2. 3 : 4
3. 4 : 3
4. 9 : 16

✅ Correct Answer: 2

A rubber cord of cross sectional area 1 mm² and unstretched length 10 cm is stretched to 12 cm and then released to project a stone of mass 5 gram. If Y for rubber = 5 ? 108N/m², then the tension in the rubber cord is

1. 25 N
2. 50 N
3. 100 N
4. 200 N

✅ Correct Answer: 3

Out of the following materials, whose elasticity is independent of temperature?

1. Copper
2. Invar steel
3. Brass
4. Silver

✅ Correct Answer: 2

An iron bar of length l m and cross section A m² is pulled by a force of F Newton from both ends so as to produce and elongation in meters. Which of the following statement statements is correct

1. Elongation is inversely proportional to length l
2. Elongation is directly proportional to cross section A
3. Elongation is inversely proportional to A
4. Elongation is directly proportional to Youngs modulus

✅ Correct Answer: 3

The ratio of the change in dimension at right angles to the applied force to the initial dimension is known as

1. Youngs modulus
2. Poissons ratio
3. Lateral strain
4. Shearing strain

✅ Correct Answer: 3

Four wires whose lengths and diameter respectively are given below are made of the same material. Which of these will have the largest extension when same tension is applied?

1. 0.50 m, 0.50 mm
2. 1.00 mm, 1.00 mm
3. 2.00 m, 2.00 mm
4. 4.00 m, 4.00 mm

✅ Correct Answer: 1

When the intermolecular distance increases due to tensile force, then

1. There is no force between the molecules
2. There is a repulsive force between the molecules
3. There is an attractive force between the molecules
4. There is zero resultant force between the molecules

✅ Correct Answer: 3

One end of a steel wire of area of cross-section 3 mm² is attached to the ceiling of an elevator moving up with an acceleration of 2.2 m/s². if a load of 8 kg is attached at its free end, then the stress developed in the wire will be

1. 8 × 106 N/m²
2. 16 × 106 N/m²
3. 20 × 106 N/m²
4. 32 × 106 N/m²

✅ Correct Answer: 4

The magnitude of the force developed by raising the temperature from 0°C to 100°C of the iron bar of 1.00 m long and 1 cm² cross-section when it is held so that it is not permitted to expand or bend is (a = 10-5/oC and Y = 1011 N/m²)

1. 103 N
2. 104 N
3. 105
4. 109 N

✅ Correct Answer: 2

The upper end of wire 1 m long and 2 mm radius is clamped. The lower end is twisted through an angle of 45°. The angle of shear is

1. 0.09°
2. 0.9°
3. 9°
4. 90°

✅ Correct Answer: 1

The radii of two wires of a same material are in ratio 2 : 1. if the wires are stretched by equal forces, the stress produced in them will be

1. 2 : 1
2. 4 : 1
3. 1 : 4
4. 1 : 2

✅ Correct Answer: 3

A number of small drops of mercury coalesce adiabatically to form a single drop. The temperature of drop

1. Increases
2. Is infinite
3. Remains unchanged
4. May decrease or increase depending upon size

✅ Correct Answer: 4

Surface tension of a soap solution is 1.9 × 10-2N/m. work done in blowing a bubble of 2.0 cm diameter will be

1. 7.6 × 10-6 p J
2. 15.2 × 10-6 p J
3. 1.9 × 10-6 p J
4. 1 × 10-4 p J

✅ Correct Answer: 2

Plants get water through the roots because of

1. Capillarity
2. Viscosity
3. Gravity
4. Elasticity

✅ Correct Answer: 1

Choose the wrong statement from the following.

1. Small droplets of a liquid are spherical due to surface tension
2. Oil rises through the wick due to capillarity
3. In drinking the cold drinks through a straw, we use the phenomenon of capillarity
4. Gum is used to stick two surfaces. In this process we use the property of Adhesion

✅ Correct Answer: 3

The height of a liquid in a fine capillary tube

1. Increases with an increase in the density of a liquid
2. Decreases with a decrease in the diameter of the tube
3. Decreases with an increase in the surface tension
4. Increases as the effective value of acceleration due to gravity is decreased

✅ Correct Answer: 4

At critical temperature, the surface tension of a liquid

1. Is zero
2. Is infinity
3. Is the same as that at any other temperature
4. Can not be determined

✅ Correct Answer: 1

A capillary tube when immersed vertically in a liquid records a rise of 3 cm. if the tube is immersed in the liquid at an angle of 60° with the vertical, then length of the liquid column along the tube will be

1. 2 cm
2. 3 cm
3. 6 cm
4. 9 cm

✅ Correct Answer: 3

When the angle of contact between a solid and a liquid is 90°, then

1. Cohesive force > Adhesive force
2. Cohesive force < Adhesive force
3. Cohesive force = Adhesive force
4. Cohesive force >> Adhesive force

✅ Correct Answer: 3

Water rises up to a height of 5 cm in a capillary tube of radius 2 mm. what is the radius of the radius of the capillary tube if the water rises up to a height of 10 cm in another capillary?

1. 4 mm
2. 1 mm
3. 3 mm
4. 1 cm

✅ Correct Answer: 2

If the surface of a liquid is plane, then the angle of contact of the liquid with the walls of container is

1. Acute angle
2. Obtuse angle
3. 90°
4. 0°

✅ Correct Answer: 4

Two soap bubbles have radii in the ratio of 4 : 3. What is the ratio of work done to below these bubbles?

1. 4 : 3
2. 16 : 9
3. 09 : 16
4. 3 : 4

✅ Correct Answer: 2

The height of water in a capillary tube of radius 2 cm is 4 cm. what should be the radius of capillary, if the water rises to 8 cm in tube?

1. 1 cm
2. 0.1 cm
3. 2 cm
4. 4 cm

✅ Correct Answer: 1

Water rises up to a height of 4 cm, in a capillary tube immersed vertically in water. What will be the length of water column in the capillary tube, if the tube is immersed in water, at an angle of 60° with the vertical?

1. 4 cm
2. 6 cm
3. 8 cm
4. 2 cm

✅ Correct Answer: 3

The surface of water in contact with glass wall is

1. Plane
2. concave
3. convex
4. Both b and c

✅ Correct Answer: 2

Pressure inside two soap bubbles is 1.01 and 1.02 atmospheres. ratio between their volume is

1. 102 : 101
2. (102)3 : (101)3
3. 8 : 1
4. 2 : 1

✅ Correct Answer: 3

One end of a towel dips into a bucket full of water and other end hangs over the bucket. It is found that after some time the towel becomes fully wet. It happens

1. Because viscosity of eater is high
2. Because of the capillary action of cotton threads
3. Because of gravitational force
4. Because of evaporation of water.

✅ Correct Answer: 2

Water rises up to a height h, in a capillary tube of radius r. the mass of the water lifted in the capillary tube is M. if the radius of the capillary tube is doubled, the mass of water that will rise in the capillary tube will be

1. M
2. 2M
3. M/2
4. 4M

✅ Correct Answer: 2