A galvanometer coil having a resistance of 20 Ω and a full-scale deflection at 1.0 mA is connected in series with a 4980 Ω resistance to build a voltmeter.What is the maximum voltage that this voltmeter can read?
A) 3.0 V
B) 1.0 V
C) 50 V
D) 5.0 V
E) 10 V

Question

Quizplus · Accepted Answer

The maximum current that can flow through the voltmeter is the full-scale deflection current of the galvanometer, which is 1.0 mA. Using Ohm's Law, we can determine the maximum voltage that can be measured:

V = IR
V = (1.0 mA)(4980 Ω + 20 Ω)
V = 5.0 V

Therefore, the maximum voltage that this voltmeter can read is 5.0 V, which is choice D.

A Galvanometer Coil Having a Resistance of 20 Ω and a Full-Scale