The magnetic field B due to a current- carrying circular loop of radius 12cm at its center is `0.50 xx (10^-4) T`. Find the magnetic field due to this loop at a point on the axis at a distance of 5.0 cm from the centre.

Explanation

Solution: The magnetic field at the centre of a circular
loop is
` B_0=((mu_0)i/2a)`
and that at an axial point is
`B= (((mu_0)ia^2)/2((a^2 + x^2)^3/2))`
` Thus, (B/B_0)= (a^3/((a^2+x^2)^3/2))`
or, B= (0.50 xx (10^-4) T) xx (((12 cm)^3)/(((144cm^2) + (25cm^2))^3/2))`
`= 3.9 xx (10^-5) T.