Briefly answer the following questions:
1. In the below figure you find that the bulb glows when an metal pin is placed between two ends of wire. Complete the following sentences on the bases of this fact.
Electric circuit
1. makes the bulb in the circuit to glow.
2. In the above figure if the iron nail is replaced by a plastic, will the bulb glow or not? Justify your answer.
i. .
ii. It acts as an .