Question

In a household electric circuit, which if the following is/are correct?
(A) All electrical appliances drawing power are connected in parallel.
(B) A switch may either be in series or parallel with the appliance which it controls.
(C) If a switch is in parallel with an appliance, it will draw power when the switch is in the off(open) position.
(D) If a switch is in parallel with an appliance, the fuse will blow (burn out) when the switch is put on(closed).

A) A, D
B) A, C, D
C) B, C, D
D) A, B, D

Answer 1

Hint: We analyze each of the situations and see which of the options are correct. We need to know two main points of an electric circuit to solve this,
-In a parallel circuit even if one appliance is off other appliances will work.
-In a series circuit there is only one path for electricity to flow, so if one appliance is off the rest of the circuit won’t receive current.

Complete step by step answer:
The parallel circuit is defined as the circuit where all components are connected between the same set of electrically common points. Another way of saying this is that all components are connected across each other's terminals. The current can flow in various paths in the parallel circuit.

A series circuit is defined as a circuit in which resistors are arranged in a chain, so there is only one path for the current to flow.

Now solving the question,

In the household, if the appliances are connected in series, if one appliance is turned off then the whole circuit breaks and all others will get turned off. So, they are always connected in parallel so that we can use appliances independent of others.

The switch of an appliance must be connected in series because the purpose of a switch is to turn off/on (break and connect the circuit). So, when we connect the switch in series, the appliance turns on when the switch is closed, that means the circuit is connected and the appliance is turned off when the switch is open, that is, breaking the circuit.

If the switch is connected in parallel, even when it is off(open) the appliance draws power because the current can flow in a different path.

When the switch is connected in parallel and is on(closed) the terminals of the appliance get short-circuited and blow the fuse. In the on(closed) condition it gets short-circuited because both the positive and negative terminals are connected directly.

Hence option (B) A, C, D is the correct answer.

Note:When a switch is connected in parallel and is in the closed condition the positive and negative terminals meet directly in the path of the switch located. A common example of a short circuit occurs when the positive and negative terminals of a battery are connected with a low-resistance conductor, like a wire.