Question

A current of 10 A is passing through a long wire which has semicircular loop of the radius 20 cm as

shown in the figure. Magnetic field produced at the centre of the loop is

• A. $10\pi \mu \text{T}$
• B. $5\pi \mu \text{T}$
• C. $4\pi \mu \text{T}$
• D. $2\pi \mu \text{T}$

Answer 1

The correct option is B

$5\pi \mu \text{T}$

$\text{B}=\frac{{\mu }_0\text{I}}{4\text{R}}=\frac{4\pi \times {10}^{-7}\times 10}{4\times 0.20}\text{T}=5\pi \times {10}^{-6}\text{T}=5\pi \mu \text{T}$.