Q. The coil of a galvanometer consists of 100 turns and effective area of $1\ square\ cm$. The restoring couple is $10^{- 8}N - m/radian$. The magnetic field between the pole pieces is $5\ T$. The current sensitively of this galvanometer will be
A) $5 \times 10^{- 4}rad/\mu\ amp$
B) $5 \times 10^{- 6}\ per\ amp$
C) $2 \times 10^{- 7}per\ amp$
D) $5\ rad/\mu\ amp$
Explanation
(d) Current sensitivity $\frac{\theta}{i} = \frac{NBA}{C}$
$\Rightarrow \frac{\theta}{i} = \frac{100 \times 5 \times 10^{- 4}}{10^{- 8}} = 5\ rad/\mu\ amp$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.