Question

A circular coil of wire of radius ' $r$ ' has ' $n$ ' turns and carries a current '$I$'. The magnetic induction ' $B$ ' at a point on the axis of the coil at a distance $\sqrt{3} r$ from its centre is

• A. $\frac{\mu_{0} nI }{16 r}$
• B. $\frac{\mu_{0} n I}{4 r}$
• C. $\frac{\mu_{0} n I}{32 r}$
• D. $\frac{\mu_{0} n I}{8 r}$

Answer 1

Answer: (A)

$B=\frac{\mu_{0} n i r^{2}}{2\left(x^{2}+r^{2}\right)^{3 / 2}}$