Question

Identify the incorrect statement from the following.

• A. In rectilinear motion, body moves in a straight line.
• B. Periodic motion is always oscillatory.
• C. The motion of a stone dropped from a roof is rectilinear.
• D. The motion of a simple pendulum is periodic.

Answer 1

The correct option is B Periodic motion is always oscillatory.

All oscillatory motions are periodic because each oscillation gets completed in a definite interval of time. Eg: a load attached to a spring executes oscillatory motion.
Periodic motion is the motion which repeats itself after equal intervals of time. All periodic motions may not be oscillatory. For example, the revolution of a planet around the Sun is a periodic motion but not an oscillatory motion.