Why is the earth pin of a three-pin plug made longer and thicker?

Explanation

### Step-by-Step Solution:

1. **Understanding the Three-Pin Plug**: A three-pin plug consists of three pins: live, neutral, and earth. The earth pin is designed for safety purposes.

2. **Length of the Earth Pin**: The earth pin is made longer than the other two pins (live and neutral) to ensure that it makes contact with the socket first when the plug is inserted. This means that the electrical circuit is grounded before the live and neutral connections are made.

3. **Safety Mechanism**: By making contact first, the earth pin helps to prevent any electrical shock or damage to appliances. If there is a fault in the appliance, the earth connection provides a safe path for the current to flow to the ground.

...