A simple pendulum (shown in Fig. 1) can be made by tying a weight (called a bob) to a length of string and then suspending it from a fixed point. By moving the bob to the right or left and releasing it, the pendulum will swing back and forth between points A and B. The distance of deflection of the bob from its resting place to point A or B is called the amplitude. The period may is defined as the time it takes for the bob to go through one cycle from point A to B and back again