Question

Study the circuit diagram below. The bulbs are labelled A,B,C,D.
The switches are labelled 1,2,3,4.
a) Which 2 switches should be closed so that only bulbs B and C would light up?
b) Which bulbs will remain lit if bulb D fuses when all the switches are closed?

Answer 1

a)2 and 3 should be closed
b)a,d,and c will remain lit

Answer 2

A) only 2nd & 3rd no switch has to closed for b & c light up
B) bulb A-b-c are remain if d fuses
B) A-B-C