(Solved): Calculate the value of the multiplier resistors R to R4 in the design of a multi-range voltmeter ...

Expert Answer

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four voltage ranges are given
Rm = internal resistance of voltmeter = 2k
let Im= full scale deflection current of meter=60 microA
Let us consider the voltmeter of voltage range 0-10 V
Here let full range voltage of instrument V 1=10 V
Let voltage across the meter movement for current Im = v




since current through the meter having resistance Rm is Im


R1 = multiplier resistance in the first case





since Rm and R1 are connected in series and current flowing is Im and full range voltage is V1

we know multiplying factor m= V/v





putting the values of V and v, Rn is multiplier resistance