Question

Look at the circuit diagram and answer the questions.
figure

(a) What happens when B is closed and A is open?
(b) What happens when B is open and A is closed?

Answer 1

(a) When B is closed and A is open, only bulb 4 will glow.

(b) When B is open and A is closed, bulbs 1, 2 and 3 will glow.