Question

The magnetic field $\vec{B}$ in a circular coil does not depend on:

• A. current
• B. radius
• C. number of turns
• D. area

Answer 1

Answer: (D)

area

Answer 2

The magnetic field at the centre of circular coil $B=\frac{\mu_{0} n I}{2 r}$ where $r=$ radius of coil $I=$ current flowing in the coil. $n=$ number of turns in a coil Therefore, magnetic field in a circular coil does not depend on area of coil.