Top Rotational Motion Questions for 2025 Exams with Answers
Rotational Motion is a vital chapter in JEE Main Physics, focusing on real-life applications of angular momentum, torque, and moment of inertia. Mastery of this topic is crucial for scoring high, as it builds the foundation for mechanics and advanced physics questions. Take this targeted mock test to reinforce your understanding and ace JEE-level problems in Rotational Motion!
Mock Test Instructions for the Rotational Motion Mock Test 1:
- 20 questions from Rotational Motion Mock Test 1
- Time limit: 20 minutes
- Single correct answer per question
- Correct answers appear in bold green after submission
How Can JEE Mock Tests Help You Master Rotational Motion?
- Practice mock tests to strengthen your understanding of torque, moment of inertia, and angular momentum.
- Identify common mistakes in rotational dynamics and improve accuracy using test feedback.
- Enhance speed by solving time-bound MCQs on rolling motion, angular acceleration, and radius of gyration.
- Use mock tests to target conceptual gaps and bolster weak areas before the JEE exam.
- Track your progress in rotational motion with detailed score analysis and revisit challenging problems.
Sharpen Your Problem-Solving for Rotational Motion with Vedantu’s Expert JEE Mock Tests
- Master real exam patterns using expert-created questions on rotational inertia, torque, and energy principles.
- Simulate JEE exam pressure with automated, timed chapter tests focused on rotational motion.
- Solve previous year-style MCQs and avoid common pitfalls in rotational mechanics.
- Leverage instant solutions to build conceptual clarity and formula retention for JEE Main 2025.
- Boost your confidence for the Physics section by benchmarking your performance topic-wise.
Subject-Wise Excellence: JEE Main Mock Test Links
| S.No. | Subject-Specific JEE Main Online Mock Tests |
|---|---|
| 1 | Online FREE Mock Test for JEE Main Chemistry |
| 2 | Online FREE Mock Test for JEE Main Maths |
| 3 | Online FREE Mock Test for JEE Main Physics |
Important Study Materials Links for JEE Exams
FAQs on Rotational Motion Mock Test 2025 – Practice and Solutions
1. What is rotational motion?
Rotational motion refers to the movement of a body around a fixed axis. In such motion, all points of the object move in circles about the axis, and each point on the body follows a circular path. Examples include a spinning wheel or a rotating fan.
2. What is the difference between rotational motion and circular motion?
Rotational motion involves rotation of a body about an axis passing through itself, while circular motion refers to movement of an object along the circumference of a circle. In rotational motion, the axis can be within or outside the object, whereas in circular motion, every point of the object moves along a circle, but the object itself may not be spinning.
3. Define moment of inertia and its significance in rotational dynamics.
Moment of inertia (I) is the measure of an object's resistance to changes in its rotational motion, similar to mass in linear motion. It depends on the distribution of mass relative to the axis of rotation. A higher moment of inertia means more torque is needed to change its rotational speed.
4. What is the relation between angular velocity and linear velocity in circular motion?
The relation is given by v = rω, where v is linear velocity, ω is angular velocity, and r is the radius of the circular path. This means linear velocity increases with radius for a given angular speed.
5. State the law of conservation of angular momentum with an example.
The law of conservation of angular momentum states that if no external torque acts on a system, its total angular momentum remains constant. For example, a spinning figure skater pulls in their arms to rotate faster because the moment of inertia decreases, keeping angular momentum constant and increasing angular velocity.
6. What is torque and how does it affect rotational motion?
Torque (τ) is the rotational equivalent of force. It is calculated as τ = r × F, where r is the lever arm and F is the force. Torque causes angular acceleration and changes the rotational motion of a body.
7. How is work done in rotational motion calculated?
In rotational motion, work done (W) is calculated as W = τθ, where τ is the constant torque and θ is the angular displacement in radians.
8. List two real-life examples of rotational dynamics.
Common examples of rotational dynamics include:
- The spinning of a ceiling fan (where the blades undergo rotational motion around the axis).
- The rotation of car wheels as the vehicle moves forward.
9. What is the difference between angular velocity and angular acceleration?
Angular velocity (ω) is the rate of change of angular displacement, measured in radians per second. Angular acceleration (α) is the rate of change of angular velocity, measured in radians per second squared. Angular velocity describes how fast an object rotates, while angular acceleration measures how quickly that rotation is speeding up or slowing down.
10. What do you mean by centripetal and centrifugal force in circular motion?
Centripetal force is the force directed towards the center of the circle that keeps an object moving in a circular path. Centrifugal force is a pseudo-force that appears to act outward on a mass when it is in a rotating frame of reference. In physics, only centripetal force is real and necessary for circular motion.
11. How do you calculate the kinetic energy of a rotating body?
The rotational kinetic energy of a rotating body is given by KE = (1/2) I ω2, where I is moment of inertia and ω is angular velocity.
12. What is rolling motion, and how is it different from pure rotation?
Rolling motion is a combination of both rotational and translational motion, as seen when a wheel moves on a surface. In pure rotation, the object only spins around its own axis, while in rolling motion, the object rotates and its center also moves along the surface.
