Question

A current of $10A$ is passing through a long wire which has semicircular loop of the radius $20cm$ as shown in the figure. Magnetic field produced at the centre of the loop is:

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

Answer 1

The correct option is B $5\pi \mu T$

$\begin{array}{c}B=\frac{{\mu }_{0}i}{4r}\\ =\frac{4\pi \times {10}^{-7}i\times 100}{4\times 20}\\ =5\pi \times {10}^{-7}i\\ =5\pi \times {10}^{-7}\times 10\\ =5\pi \mu T\\ Hence,\\ optionBiscorrectanswer.\end{array}$