Question

sahil took a copper wire and put both end of the wire into a plug point . the socket caught fire and the electricity in his house went off. why do u think so

Answer 1

short circuit...........

Answer 2

The reason for the fire was short circuit.
As both the positive and negative ends of the circuit were connected to each other the production of heat energy was immense. Thus, the electric socket caught fire. And, The reason for his house's electricity to go off was the breakage of the electric circuit of his house.

Hope this helps you!