Question

In a circular coil of radius r the magnetic field at the centre is proportional to

Answer 1

Answer:

1/r

Explanation:

Answer 2

Answer:

Magnetic field is inversely proportional to the radius of the coil.

Explanation:

The magnetic field at the center of a circular coil is given by

                  $B = \frac{\mu_0}{4\pi} (\frac{2\pi I}{r})$ $= \frac{\mu_0 I}{r}$ [where, B → strength of magnetic field,

                                                      I →current , r → radius of circular coil]

                             →   $B \propto \frac{1}{r}$

Therefore,magnetic field is inversely proportional to the radius of the coil.

If you increase the radius of the coil,magnetic field decreases and vice versa.