Question

The current passing through a galvanometer is 30 mA, resistance of the galvanometer is 50 Ω and a shunt is 1 Ω is connected to the galvanometer. What is the maximum current that can be measured by this ammeter?

(a) 1.53 A

(b) 15.3 A

(c) 0.153 A

(d) 153 A

The question was asked in semester exam.

My query is from Moving Coil Galvanometer in chapter Moving Charges and Magnetism of Physics – Class 12

Answer 1

Correct answer is (a) 1.53 A

The best I can explain: Given: Ig = 30 mA = 0.03 A; S = 1 Ω; G = 50 Ω

Required equation ➔ Maximum current (I) = \( [ \frac {(S + G)}{S} ] \) × Ig

I = \( [ \frac {(50 + 1)}{1} ] \) × 0.03

I = 51 × 0.03

I = 1.53 A