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The input impedance of the permanent magnet moving coil (PMMC) voltmeter is infinite. Assuming that the diode shown in the figure below is ideal, the reading of the voltmeter in Volts is

The input impedance of the permanent magnet moving coil (PMMC) voltmeter is infinite. Assuming that the diode shown in the figure below is ideal, the reading of the voltmeter in Volts is Correct Answer 4.46

PMMC reads the average value,

The circuit looks like a Half-wave rectifier circuit.

Vavg = (Vm / π)

The voltage across the 100 k Ω is the average output voltage ( V0) 

And V0 = Reading of the voltmeter

V0= (100k / (100k + 1k)) x Vavg

V0 = (100 / 101) x (Vm / π)

V0 = (100 / 101) x (14.14 / π)

V0 = 4.46 V

⇒ Voltmeter reading = 4.46 V

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