Question

In ohm's law experiment it is advised to take out the key from the plug when the observations are not being taken

Answer 1

Thanks for asking the question.

When the circuit is connected for demonstration of ohms law, current starts to flow through it due to the potential difference of the battery or cell connected. Thus it is advised to remove the key from the plug when observations are not being taken because in this way the circuit is not complete and the current doesn't flow unnecessarily which can otherwise cause depletion of voltage and overstraining of the wires.

Hope it helps.