Correct option is A
· The Megger is the instrument uses for measuring the resistance of the insulation.
· Megger consists of voltage source (EMF Source) and voltmeter.
· It works on the principle of comparison, i.e., the resistance of the insulation is compared with the known value of resistance.
· The Megger has three coils two pressure coils (control coil) and one current coil. The pressure coil rotates the moving coil in the anticlockwise direction, whereas the current coil rotates it in the clockwise direction.
· If the resistance of the insulation is high, the pointer of the moving coil deflects towards the infinity, and if it is low, then the pointer indicates zero resistance.
· The accuracy of the Megger is high as compared to other instruments.
