The magnetic field at the centre of a current carrying circular coil of an area ' A ' is ' B '. The magnetic moment of the coils is [ 0= permeability of free space.]

Step-by-step solution

The correct option is (A) 2 B A^ 3 / 2 ₀ Let r be the radius of the circular loop. A= r^2 or r= A Magnetic field at the centre of the loop is aligned & B= ₀ I 2 r = ₀ I 2 A & I= 2 B ₀ A aligned The magnetic moment of the loop is M=I A= ( 2 B ₀ A ) A= 2 B A^ 3 / 2 ₀