Q. The deflection in a moving coil galvanometer is reduced to half when it is shunted with a 40$\ \Omega$ coil. The resistance of the galvanometer is
A) 15$\ \Omega$
B) 20$\ \Omega$
C) 40$\ \Omega$
D) 80$\ \Omega$
Explanation
(c) $I \propto Q$
$\frac{I_{g}}{I} = \frac{1}{2}$
$\frac{S}{G + S} = \frac{1}{2}$
$\frac{40}{G + 40} = \frac{1}{2} \Longrightarrow G = 40\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.