Question

Which of the following is a plug key?

Answer 1

Hint: A plug key is an electronic component whose function is similar to that of a switch. A small metallic key is present which when pressed the switch turns on and when we remove it from its base the circuit gets off.

Complete step by step answer:
There are various kinds of switches. Every electrical circuit uses at least one switch to perform on and off operation. Switch keys, tapping keys, plug keys etc. in a circuit diagram representation every switch is represented using certain symbols. Even the on and off positions are shown in order to better understand the circuit.
The ON position of the plug key is demoted by the symbol on fig 1.this shows that the circuit is complete. The OFF position of the switch is shown in fig 2 .This also indicates that the switch is open.

The plug key is used in the circuit to start and stop the flow of current in the circuit.
Hence the correct answer is option (A).

Note: Option b shows a switch key whereas option C shoes a tapping key. Switch key can be activated by only using a key .It is used in cases where access had to be restricted only to the switch’s function. Tapping key is used to provide momentary activation or contact in the electrical circuits which are usually open. They are also used in Morse code applications.