Question

A 25mv, 2mA d’Arsonval movement is to be used in voltmeter whose full scale reading is 100v. The resistance inserted by 100v meter into circuit is ___________

(a) 1 * 10^5Ω

(b) 1 * 10^6Ω

(c) 1 * 10^4Ω

(d) 1 * 10^3Ω

I have been asked this question at a job interview.

Question is from Measuring Voltage and Current in division Simple Resistive Circuits of Electric Circuits

Answer 1

The correct answer is (a) 1 * 10^5Ω

Easy explanation: v = iR

                               R = v/i

                                  = 100/1mA

                                  = 100,000Ω.