The coild of a galvanometer consists of 100 turn and effective area `1 cm^(2)`. The restoring couple is `10^(-8) n-m//rad`. The magnetic field between the pole pieces `5` tesla. The current sensitivty per micro ampere.

Options

A. `2 xx 10^(-7)`peramp
B. `5 rad/mu` amp
C. `5 xx 10^(2)rad`/mu amp
D. `5 xx 10^(-6)` per amp

Answer

B

Explanation

`n=100,A=1 cm^(2)=(10^(-2))^(2)=10^(-4)m^(2),B= 5T and C=tau=10^(-8)N-m/(radian)` Current senstivity `theta/i=(nAB)/C =(100xx10^(-4)xx5)/(10^(-8))=5 xx 10^(6)`rad/A `=(5 xx10^(6)radian)/(10^(6)muA)=5rad/muA`