A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milli ampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 V, the resistance in Ohm needed to be connected in series with the coil will be-
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Question

A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milli ampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 V, the resistance in Ohm needed to be connected in series with the coil will be-

Options

G1 Physics · Accepted Answer

Current sensitivity 10 div/mA gives full-scale current 15 mA. Voltage sensitivity 2 div/mV means 1 division corresponds to 0.5 mV, so galvanometer resistance=(0.5 mV)/(0.1 mA)=5 Ω. For 1 V/div, full-scale voltage is 150 V, so total resistance=150/0.015=10000 Ω. Series resistance=9995 Ω, option D.