Correct Option: C

Three wires enter most homes from the power pole—two “hot” wires and a third “neutral” wire. Each hot wire provides 120-volt current for conventional lights, receptacles, and appliances when paired with the neutral wire, which is normally kept at zero volts or “ground potential.” When both hot wires are used together with the neutral, they power large 240-volt appliances such as air conditioners and electric ovens. All the electric appliances stop working in a house when the main switch is put off because the electric circuit (the path where the electricity travels) gets opened. A circuit needs to be closed in order for current to flow through it and thus all electric appliances to work. Switching off the main supply involves breaking the circuit and hence the current flow through the circuit. Turning off a wall switch does not necessarily turn off the power to a fixture or receptacle; the power at the circuit breaker should be shut off. On the electrical box, we can see a row of switch. One main switch is particular unique in colour or size. This is the main switch which cuts off the supply from live and neutral wire. In rest of the switches, only the live wire is disconnected. This is an important note to take, and the same applies to the wall switches.