Free Rotational and Circular Motion MCQs with Answers

• A. 7.3 x 10 radians/second
• B. 7.3 x 5 radians/second
• C. 3.7 x 10 7.3 x 5 radians/second
• D. 7.3 x 10^-5 radians/second

Explanation: Earth completes one rotation, 2π radians, in 24 hours = 86400 s. Thus angular speed = 2π/86400 rad/s = 7.27 x 10^-5 rad/s, approximately…

• A. 4 rad. S-1
• B. 5 rad. S-1
• C. 1.6 rad. S-1
• D. 2.8 ms-1

Explanation: Linear speed and angular speed are related by v = rω. Hence, ω = v/r = 2 m/s ÷ 0.4 m = 5 rad/s.

• A. Angular displacement
• B. Angular velocity
• C. Angular acceleration
• D. None of these

Explanation: Displacement, velocity and acceleration are vector quantities as they have magnitude and direction associated with them.

• A. v2 = GM/r
• B. v2= √GM/r
• C. v2= √r/GM
• D. v2= √2GM/r
• E. v2= √2r/GM

Explanation: In a circular orbit, the gravitational force on the satellite provides the necessary centripetal force to keep the satellite moving in a…

• A. ml2
• B. 1/2 ml2
• C. 1/3 ml2
• D. 2/5 ml2
• E. 1/12 ml2

Explanation: The moment of inertia of a thin rod of mass m and length l about an axis passing through its center of mass and perpendicular to its…

• A. 5/2 mr2
• B. 2/5 mr2
• C. 1/2 mr2
• D. 1/3 mr2
• E. mr2

Explanation: The moment of inertia of a solid sphere about a line passing through its center is given by the formula:I = (2/5)mr²where m is the mass of…

• A. MLT
• B. MLT-1
• C. MLT-2
• D. M0L-2T-3
• E. M0L0T-1

Explanation: Angular velocity is defined as the rate of change of angular displacement with respect to time.

• A. Acute angle
• B. Obtuse angle
• C. Right angle
• D. Supplementary angle

Explanation: Correct. The velocity of the electron is tangential, and the radius is radial, making them perpendicular.

• A. Turning effect of force
• B. Cross product of position vector and force
• C. Product of force and moment arm
• D. All A, B and C are correct

Explanation: Torque is the turning effect of a force and is defined vectorially by τ = r x F, while its magnitude is force multiplied by the…

• A. Angular Momentum
• B. Linear momentum
• C. kinetic energy
• D. none of these

Explanation: Angular momentum is conserved when there is no external torque acting on the system.

• A. along the axis
• B. along tangent
• C. directed towards center
• D. directed away from center

Explanation: he linear velocity of a body moving in a circle is always directed along the tangent to the circle at the point where the body is located.

• A. 180⁰
• B. 0⁰
• C. 90⁰
• D. 45⁰The angle between linear velocity (\( v \)) and angular velocity (\( \omega \)) for a body moving in a circle is always 90°. This is because linear velocity is tangential to the circle, while angular velocity is directed along the axis of rotation.

Explanation: The angle between linear velocity (\( v \)) and angular velocity (\( \omega \)) for a body moving in a circle is always 90°.

• A. a= alphaxr v
• B. a= rxalpha
• C. a= alphaxr
• D. a= ax alpha

Explanation: This is correct. This equation represents the fundamental relationship between linear and angular acceleration for a point on a rotating…

• A. Linear Momentum
• B. Linear Kinetic Energy
• C. Angular Kinetic Energy
• D. Angular Momentum

Explanation: According to the law of conservation of angular momentum, if no external torque acts on a system, the angular momentum remains constant.

• A. Tangent to the circle
• B. Inward the circle
• C. Axis of rotation
• D. outward of the rotation

Explanation: Angular momentum is a vector quantity directed along the axis of rotation according to the right-hand rule.

• A. 1N
• B. 10N
• C. 2N
• D. 100N

Explanation: The outward force acting on a rotating mass is the tension in the string, which is equal to the centripetal force.

• A. At the highest point
• B. At the lowest point
• C. At any point during motion
• D. At the point where gravity is not acting

Explanation: The tension in the string is maximum at the bottom (lowest point) of the vertical circle, and if this tension exceeds the strength of the…

• A. Tangential acceleration \(= rv^2\) and Centripetal acceleration \(= 0\)
• B. Tangential acceleration \(= v^2/r\) and Centripetal acceleration \(= 0\)
• C. Tangential acceleration \(= 0\) and Centripetal acceleration \(= rv^2\)
• D. Tangential acceleration \(= 0\) and Centripetal acceleration \(= v^2/r\)

Explanation: When a body moves at a constant speed in a circular path, its tangential acceleration is \(a_t = \frac{v^2}{r}\) and its centripetal…

• A. \( F = ma \)
• B. F = Delta p/Delta t
• C. tau = I \alpha
• D. All of these

Explanation: In angular motion, Newton's second law is expressed as \( \tau = I \alpha \), where \( \tau \) is the torque, \( I \) is the moment of…

• A. Along the axis of rotation
• B. Along the tangent
• C. Directed towards the center
• D. Directed away from the center

Explanation: The linear velocity of a body moving in a circle is always directed along the tangent to the circle at the point where the body is…