Question

A charge q is circulating in an orbit of radius r making n revolutions per second. The magnetic field produced at the center of the circle inTesla is

• A. $\frac{2\pi q}{nr}\times {10}^{-7}$
• B. $\frac{2\pi q}{r}\times {10}^{-7}$
• C. $\frac{2\pi nq}{r}\times {10}^{-7}$
• D. $\frac{2\pi rq}{q}\times {10}^{-7}$

Answer 1

The correct option is C $\frac{2\pi nq}{r}\times {10}^{-7}$

$B=\frac{{\mu }_{0}nq}{2r}B=\frac{4\pi \times {10}^{-7}\times nq}{2r}=\frac{2\pi nq}{r}\times {10}^{-7}$