Free, Damped and Forced Oscillations — Important Questions

It is converted into heat and never returned to the body

Energy dissipated during damping is converted into heat due to friction and is not returned to the oscillating body.

Oscillation of a body under an external periodic force with the frequency of that force

In forced oscillations, an external periodic force makes the body oscillate with the force's frequency, not its own natural frequency.

A force whose magnitude and direction change periodically with time

A periodic force repeats itself at regular time intervals in both magnitude and direction.

A bob suspended by a thread oscillating at its natural frequency

A bob suspended by a thread and left free oscillates at its own natural frequency, so it is an example of free or natural oscillation.