A rectangular coil of effective area `0.05 m^(2) ` is suspended freely in aradiul magnetic field of 0.001 `Wb//m^(2)`. The torsional constant of the suspension fibre is `5 xx 10^(-9)Nm`/degree. If a current of 300muA is passed through it, then the angle through which the coil rotates is

Options

A. 30◦
B. 45◦
C. 60◦
D. 90◦

Answer

A

Explanation

`I=(Ktheta)/(nBA) therefore theta=(nIAB)/K = (1 xx 300 xx 10^(-6) xx 5 xx 10^(-2) xx 10^(-2))/(5 xx 10^(-9)) therefore theta=30◦`