Question

what is periodic motion explain with the help of two examples

Answer 1

Periodic motion, in physics, motion repeated in equal intervals of time. 
Examples of periodic motion include a rocking chair, swing, tuning fork, and a pendulum. A satellite orbiting our planet and a mass bouncing on a spring are also examples of periodic motion

Answer 2

A motion is said to be periodic if it repeats itself after a regular interval time. Or
A motion which repeats itself after equal interval of time is called periodic motion
ex-1 revolution of moon
2 the motion of hands of the clock