Q. The resistance of a galvanometer is $25\ ohm$ and it requires $50\ \mu A$ for full deflection. The value of the shunt resistance required to convert it into an ammeter of $5\ amp$ is
A) $2.5 \times 10^{- 4}ohm$
B) $1.25 \times 10^{- 3}ohm$
C) $0.05\ ohm$
D) $2.5\ ohm$
Explanation
(a) $S = \frac{G}{\frac{i}{i_{g}} - 1} = \frac{25}{\frac{5}{50 \times 10^{- 6}} - 1} = \frac{25}{10^{5} - 1} = \frac{25}{10^{5}} = 2.5 \times 10^{- 4}\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.