An electric circuit is given below.
Study the circuit and explain why all the bulbs did not light up when the switch (S) was closed?
I. The metal tip of bulb B1 was not connected.
II. Bulb B2 and the alloy metal key closed the electric
circuit.
III. The plastic disposable spoon was not an electrical
conductor.
IV. Bulbs B1 and B3 were incorrectly positioned in the electric circuit.
AI only
BIII only
CI, II and IV only
DI, III and IV only
Isn't the metal tip of bulb B1 not connected, and hence 1 should also be considered as a reason?