Given a battery, two switches and an electric bulb, how can (i) an OR gate and (ii) an AND gate be constructed?

Explanation

If the switch is made on or, off, the bulb glows or exinguishes. Hence, the two swithces are the input and the bulb is the output.

The circuit shown in Fig. 2.32(a) is an OR gate circuit, because when any one or both the swichtes, A and B are on, the bulb Y will glow.
The circuit shown in Fig. 2.32(b) is an AND gate circuit, because only when both the swithces A and B are on, the bulb Y will glow.