What is the expression for the time period of a simple pendulum?

The simple pendulum comprises a small bob of mass ‘m’ suspended by a thin string secured to a platform at its upper end of length (l).

The simple pendulum is a mechanical system that sways or moves in an oscillatory motion. This motion occurs in a vertical plane and is mainly driven by gravitational force. 

The time period of a simple pendulum is defined as the time taken by the pendulum to finish one full oscillation and is denoted by “T”. Its expression is given as: 

$T = \frac{1}{2\pi }\sqrt{\frac{l}{g}}$