Question

Calculate the reading of voltmeter when 110 V 50 Hz is supplied across PMMC voltmeter having internal resistance 10 kΩ and full-scale range of 0-220 V.
1. 55 V
2. 78 V
3. 110 √2 V
4. 0 V

Answer 1

Correct Answer - Option 4 : 0 V

Concept:

Permanent Magnet moving coil type (PMMC) is used only for DC. It responds to DC quantities only. For alternating quantities, the torque in the coil becomes zero and hence there will be no deflection.

Application:

As the applied voltage is AC the reading is zero.