What is the main difference in the wiring of an electric bulb and a socket for using an electric iron in a domestic electric circuit? What is the reason for this difference?

The main difference in the wiring of an electric bulb and a socket for using an electric iron in a domestic electric circuit is, an earth connection is given to the socket for electric iron, whereas no earth connection is given to an electric bulb.

The reason for this difference is because earth connections are given to only those appliances that have a metallic body, draw heavy current and can be touched. That's why an electric iron is provided with earth connection.

However, earthing is not required for the electric bulb connection as it does not draw heavy current and we hardly touch it when it is on.