Question

Motion that moves to and fro in regular time intervals is called ________ motion .

Answer 1

1. The to and fro (repeated) motion of an object from its mean position is called oscillatory motion.
2. An object in such motion oscillates about an equilibrium position due to restoring forces.

Examples: Vibrating strings of musical instruments and oscillations of a simple pendulum.

Hence, the motion that moves to and fro in regular time intervals is called vibratory or oscillatory motion.