The diagram shows a simple pendulum consisting of a mass M suspended by a thin, massless string. The magnitude of the tension is T. The mass swings back and forth between o.

T= Mg at some angle between zero and o.

The vertical component of tension is constant.

T= Mg at = o

T is largest at the bottom ( = 0)o.

T is smallest when = o

T is greater than Mg when = o.