An electrical switch is any device used to interrupt the flow of electrons in a circuit. Switches are essentially binary devices: they are either completely on (“closed”) or completely off (“open”).

A switch is always connected to live wire. The purpose of the switch is to break or connect an electric circuit, but they must be correctly connected at home.

If the switches are connected to neutral wire, no current will flow through the appliance and hence it will not operate.

Commonly used switches are lever type. By moving the lines upward, a given circuit is switched off and vice-versa.

When an appliance is in contact with the live wire, its heating element will be at same potential as the live wire and current will flow.

MCB stands for Miniature circuit breakers which opens the circuit when excessive current passes through the appliance and thus prevents the appliance from any damage.

Single pole switch is used with an appliance to start or stop the flow of current in it.

In the household if the appliances are connected in series, if one appliance is turned off then the whole circuit breaks and all other will get turned off. So they are always connected in parallel so that we can use appliances independent of other.
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 turn's on when switch is closed and off when open.
If the switch is connected in parallel, even when it is off(open) the appliance draws power and when it is on the terminals of the appliance gets shorted and blows the fuse.

In the household if the appliances are connected in series, if one appliance is turned off then the whole circuit breaks and all other will get turned off. So they are always connected in parallel so that we can use appliances independent of other.
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 turn's on when switch is closed and off when open.
If the switch is connected in parallel, even when it is off(open) the appliance draws power and when it is on the terminals of the appliance gets shorted and blows the fuse.

A switch is a device that is used to  open or close a circuit to control the flow of current in a circuit.

Each local circuit in a room is provided with a seperate switcho switches are connected in the live wire, so that when the switch is in the off portion, no point of the connected electric appliance will be at higher potential.

All appliances in houses are connected parallel so that even if one get damaged , others will work properly and all appliances are independent .
If switch is connected in parallel, there will be short circuit when  switch is on and hence fuse will be blown and when switch is off, the appliance will draw power and there won't be any short circuit.

Switch must be connected to the live wire so that it can disconnect the circuit when it is switched off.