Q. A galvanometer of resistance $20\ \Omega$ is to be converted into an ammeter of range $1\ A.$ If a current of $1\ mA$ produces full scale deflection, the shunt required for the purpose is
A) $0.01\ \Omega$
B) $0.05\ \Omega$
C) $0.02\ \Omega$
D) $0.04\ \Omega$
Explanation
(c) $\frac{i}{i_{g}} = 1 + \frac{G}{S} \Rightarrow \frac{1}{10^{- 3}} = 1 + \frac{20}{S} \Rightarrow S = \frac{20}{900} \approx 0.02\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.