NEET Physics: Basic concepts of rotational motion Practice Questions
15 free multiple-choice questions on Basic concepts of rotational motion (Rotational Motion) for NEET Physics, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. Which physical quantity measures the amount of rotation of a body divided by the radius of the circle traced by the body?
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Correct answer: D — Angular displacement
Angular displacement (θ) is defined as the ratio of the arc length (the amount of rotation) to the radius of the circle (s/r), which is the fundamental concept of rotational movement.
Q2. If the angular velocity of a body is constant, what can be inferred about its angular acceleration?
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Correct answer: C — Angular acceleration is zero
If angular velocity is constant, the rate of change of angular velocity (angular acceleration) must be zero.
Q3. The relationship between linear acceleration (a) and angular acceleration (α) for a body rotating about a fixed axis is given by:
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Correct answer: D — a = αr
The linear acceleration (a) of a point on the rim is related to the angular acceleration (α) and the radius (r) by the formula a = rα.
Q4. The rotational equivalent of force is known as:
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Correct answer: A — Torque
Torque (τ) is the rotational equivalent of force. It measures the effect of a force on the rotational motion.
Q5. The SI unit used to measure angular velocity is:
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Correct answer: A — Radian per second
Angular velocity is the rate of change of angular displacement. The SI unit for angular displacement (radian) is radian per second (rad/s).
Q6. Which of the following physical quantities is a vector quantity in rotational motion?
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Correct answer: B — Torque
Angular momentum is the rotational analogue of linear momentum and is a vector quantity, having both magnitude and direction of rotation (defined by the axis of rotation).
Q7. A body is rotating with a constant angular velocity. If the radius of the circular path it traces is doubled, what happens to its angular momentum?
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Correct answer: B — It is doubled
Angular momentum is proportional to the moment of inertia (L = Iω). If the radius doubles, the moment of inertia increases (assuming uniform mass distribution), thus the angular momentum also doubles.
Q8. When a body is rotated, the change in its rotational kinetic energy depends primarily on:
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Correct answer: A — The mass and the square of the angular velocity
Rotational kinetic energy is given by Kᵣₒₜ = 1/2 I ω². It depends on the moment of inertia (I) and the square of the angular velocity (ω²).
Q9. The property of an object that measures its resistance to change in rotational motion is called:
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Correct answer: C — Moment of Inertia
Moment of Inertia (I) is the rotational analogue of mass, representing the resistance to changes in rotational motion.
Q10. If a body is rotating at a constant rate, what is the value of its angular acceleration?
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Correct answer: A — Zero
Angular acceleration is defined as the rate of change of angular velocity. If the angular velocity (ω) is constant, the angular acceleration (α) must be zero.
Q11. If a body rotates at a constant angular velocity, its angular acceleration is:
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Correct answer: C — Zero
Angular acceleration is the rate of change of angular velocity. If the angular velocity is constant, the angular acceleration must be zero.
Q12. Moment of inertia of a body is a measure of its:
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Correct answer: D — Resistance to changes in rotational motion
Moment of inertia (I) is the rotational analogue of mass (m), quantifying an object's resistance to changes in its state of rotation.
Q13. If a body rotates with a constant angular velocity, what can be said about its angular acceleration?
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Correct answer: B — Angular acceleration is zero
If the angular velocity (ω) is constant, the angular acceleration (α= dω/dt) must be zero.
Q14. Angular momentum of a body is conserved if the net external torque acting on it is:
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Correct answer: C — Zero
The principle of conservation of angular momentum states that angular momentum remains constant if the net external torque acting on the system is zero.
Q15. What is the angular displacement of a particle moving along a circular path?
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Correct answer: B — The angle subtended at the center of the circle
Angular displacement (θ) is the angle swept out by the radius vector from the initial position to the final position, measured in radians.
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