Question

The magnetic field at point P on the axis of a circular loop of radius R, carrying current I, at a distance x from the centre is:

Options

• \[B = \frac{\mu_0 I R^2}{2(x^2+R^2)^{3/2}}\]

• \[B = \frac{\mu_0 I R^2}{(x^2+R^2)^{3/2}}\]

• \[B = \frac{\mu_0 I R}{2(x^2+R^2)^{3/2}}\]

• \[B = \frac{\mu_0 I R^2}{2(x^2+R^2)}\]

Answer 1

The exact axial field of a circular loop of radius R carrying current I at an axial distance x is \(B = \frac{\mu_0 I R^2}{2(x^2+R^2)^{3/2}}\). This is the starting point of the magnetic dipole derivation.