Question

A coil having $N$ turns carry a current as shown in the figure. The magnetic field intensity at point $P$ is:

• A. $\frac{\mu_{0} N i R^{2}}{2\left(R^{2}+x^{2}\right)^{3 / 2}}$
• B. $\frac{\mu_{0} N i}{2 R}$
• C. $\frac{\mu_{0} N i R^{2}}{(R+x)^{2}}$
• D. zero

Answer 1

Answer: (A)

From the formula, magnetic field intensity at point $P$, shown in given figure while coil carry current $i$ and having $N$ turns is given by
$\frac{\mu_{0} N i R^{2}}{2\left(R^{2}+x^{2}\right)^{3 / 2}}$