ROTATIONAL MOTION

How does the length of a rod affect the torque of a couple applied at its ends?

• No effect
• Longer rod decreases torque
• Longer rod results in greater torque for the same force
• Torque becomes zero

What is the motion of a freely pivoted rod when a couple acts on it?

• It moves linearly
• It remains stationary
• It vibrates rapidly
• It undergoes pure rotation about the pivot

Why is the Earth's magnetic field able to align a compass needle?

• Because it attracts the entire needle
• Because it charges the needle
• Because it increases the needle's mass
• Because it applies a torque through a couple until the needle is aligned

What happens if the two forces in a couple are made to act along the same line?

• The net force increases
• The torque doubles
• The rotation becomes faster
• The net torque becomes zero

What is the role of force direction in determining rotational motion of a rod?

• It determines the mass
• It affects only translational motion
• It changes the length of the rod
• It determines whether torques add up or cancel