A simple pendulum of length l and mass (bob) m is suspended vertically. The string makes an angle `theta` with the vertical. The restoring force acting on the pendulum is

Options

A. `mg tan theta`
B. `-mg sin theta`
C. `mg sin theta`
D. `-mg cos theta`

Explanation

To find the restoring force acting on a simple pendulum when it is displaced at an angle θ from the vertical, we can follow these steps:

### Step 1: Identify the Forces Acting on the Bob
The forces acting on the bob of the pendulum are:
1. The weight of the bob, which is directed downward and has a magnitude of \( mg \).
2. The tension in the string, which acts along the string towards the pivot point.