NEET Physics Chapter Wise Mock Test – Rotational Motion

NEET Physics Chapter Wise Mock Test – Rotational Motion

Question 1:
The drive shaft of an automobile rotates at 3600 rpm and transmits 80 HP up from the engine to the rear wheels. The torque developed by the engine is
(a) 16.58 Nm
(b) 0.022 Nm
(c) 158.31 Nm
(d) 141.6 Nm

Question 2:

Question 3:
When a ceiling fan is switched on, it makes 10 revolutions in the first 3s. Assuming a uniform angular acceleration, how many rotation it will make in the next 3s?
(a) 10
(b) 20
(c) 30
(d) 40

Question 4:

Question 5:

Question 6:
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?
(a) Moment of inertia
(b) Angular momentum
(c) Angular velocity
(d) Rotational kinetic energy

Question 7:

Question 8:
If r denotes the distance between sun and the earth, then the angular momentum of the earth around the sun is proportional to
(a) r³/r
(b) r
(c) √r
(d) r²

Question 9:

Question 10:

Question 11:
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
(a) L/4
(b) 2L
(c) 4L
(d) L/2

Question 12:
In an orbital motion, the angular momentum vector is
(a) along the radius vector
(b) parallel to the linear momentum
(c) in the orbital plane
(d) perpendicular to the orbital plane

Question 13:

Question 14:

Question 15:

Question 16:
When the disc rotates with uniform angular velocity. Which of the following is not true?
(a) The sense of rotation remains same
(b) The orientation of the axis of rotation remains same
(c) The speed of rotation is non-zero and remains same
(d) The angular acceleration is non-zero and remains same

Question 17:

Question 18:
A thin and circular disc of mass M and radius R is rotating in a horizontal plane about an axis passing through its centre and perpendicular to its plane with an angular velocity ω. If another disc of same dimensions but of mass M/4 is placed gently on the first disc coaxially, then the new angular velocity of the system is
(a) 5ω/4
(b) 2ω/3
(c) 4ω/5
(d) 3ω/2

Question 19:
A solid sphere, disc and solid cylinder all of the same mass and made up of same material are allowed to roll down (from rest) on inclined plane, then
(a) solid sphere reaches the bottom first
(b) solid sphere reaches the bottom late
(c) Disc will reach the bottom first
(d) All of them reach the bottom at the same time

Question 20:
An inclined plane makes an angle 30° with the horizontal. A solid sphere rolling down this inclined plane from rest without slipping has a linear acceleration equal to
(a) g/3
(b) 2g/3
(c) 5g/7
(d) 5g/14

Question 21:
A circular disc rolls down an inclined plane. The ratio of rotational kinetic energy to total kinetic energy is
(a) 1/2
(b) 1/3
(c) 2/3
(d) 3/4

Question 22:

Direction (Q. NOs. 23-29): In each of the following questions a statement of Assertion is given followed by a corresponding statement of Reason just below it. Of the statement mark the correct answer as
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.

Question 23:
Assertion (A): A person standing on a rotating platform suddenly stretched his arms, the platform slows down.
Reason (R): A person by stretching his arms increases the moment of inertia and decreases angular velocity.

Question 24:

Question 25:
Assertion (A): If a particle moves with a constant velocity, then angular momentum of this particle about any point remains constant.
Reason (R): Angular momentum has the units of Planck’s constant

Question 26:
Assertion (A): The speed of whirlwind in a tornado is alarmingly high.
Reason (R): If no external torque acts on a body, its angular velocity remains conserved.

Question 27:
Assertion (A): Power associated with torque is product of torque and angular speed of the body about the axis of rotation.
Reason (R): Torque in rotational motion is analogue to force in translatory motion.

Question 28:
Assertion (A): For system of particles under central force field, the total angular momentum is conserved.
Reason (R): The torque acting on such a system is zero.

Question 29:
Assertion (A): There are very small sporadic changes . in the speed of rotation of the earth.
Reason (R): Shifting of large air masses in the earth’s atmosphere produce a change in the moment of inertia of the earth causing its speed of rotation to change.

Question 30:

Question 31:

Question 32:
A solid cylinder of mass 50 kg and radius 0.5 m is, free to rotate about the horizontal axis. A massless string is wound round the cylinder with one end attached to it and other hanging freely. Tension in the string required to produce an angular acceleration of 2 revolution s^-2 is
(a) 25 N
(b) 50 N
(c) 78.5 N
(d) 157 N

Question 33:
The ratio of the acceleration for a solid sphere (mass m and radius R) rolling down an incline of angle θ without slipping and slipping down the incline without rolling is
(a) 5 : 7
(b) 2 : 3
(c) 2; 5
(d) 7 : 5

Question 34:

Question 35:
A small object of uniform density rolls up a curved surface with an initial velocity v. It reaches upto a maximum height of 3v²/4g with respect.to the initial position. The object is
(a) ring
(b) solid sphere
(c) hollow sphere
(d) disc

Answers:

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