Question

WHY SHOULD WE KEEP CIRCUIT CLOSED FOR LONGER TIME AND OPEN FOR LONGER TIME TO ENSURE MINIMUM CHANGES IN VALUE OF RESISTANCE

Answer 1

Due to the temperature rise in the resistors.

Whenever we close the cicuit for long time the current flowing through the resistance makes the resistor hot.

Then if temperature rises the resistance will also rise.

So in order to lowere down the temperature the key is opened for long time☺