A galvanometer with a resistance of 40.0 Ω deflects full scale at a current of 2.0 mA.What resistance should be used with this galvanometer in order to construct a voltmeter that can read a maximum of 50 V?
A) 25 kΩ
B) 27 kΩ
C) 29 kΩ
D) 31 kΩ
E) 35 kΩ

Question

Quizplus · Accepted Answer

The correct answer is A because the total resistance of the voltmeter must be 50 V / 2 mA = 25 kΩ. The resistance of the galvanometer is 40 Ω, so the additional resistance needed is 25 kΩ - 40 Ω = 24.96 kΩ.

A Galvanometer with a Resistance of 40