Question

How many number of turns of circular coil of radius 12.56 cm and current 1 A will produce the magnetic induction of $5\times {10}^{-5}$ T at its centre ?

• A. 5
• B. 10
• C. 15
• D. 20

Answer 1

The correct option is B 10

$\begin{array}{c}B=\frac{{\mu }_{\circ }Ni}{2r}\\ N=\frac{5\times {10}^{-5}\times 2\times 12.56\times {10}^{-2}}{24M\times {10}^{-7}\times 1}\\ N=9.99\\ Hence,\\ N=10\end{array}$

So, option $B$ is correct.