A wire of length $L$ is bent in the form of a circular coil and current $i$ is passed through it. If this coil is placed in a magnetic field then the torque acting on the coil will be maximum when the number of turns is

Question

Dr. Abubacker · Accepted Answer

(d) $	au_{\max} = MB$ or $	au_{\max} = ni\pi r^{2}B$. Let number of turns in length $l$ be $n$, so $l = n(2\pi r)$ or $\alpha = \frac{l}{2\pi n}$
$\Rightarrow \ 	au_{\max} = \frac{ni\pi Bl^{2}}{4\pi^{2}n^{2}} = \frac{l^{2}iB}{4\pi\ n_{\min}} \Rightarrow 	au_{\max} \propto \frac{1}{n_{\min}} \Rightarrow n_{\min} = 1$

Q. A wire of length $L$ is bent in the form of a circular coil and current $i$ is passed through it. If this coil is placed in a magnetic field then the torque acting on the coil will be maximum when the number of turns is

Explanation

Reviewed by Dr. Abubacker

Want more practice?