A circular loop of radius 4.0 cm is placed in a horizontal plane and carries an electric current of 5.0 A in the clockwise direction as seen from above. Find the magnetic field (a) at a point 3.0 cm above the centre of the loop (b) at a point 3.0 cm below the centre of the loop.

Explanation

(a) `B = (mu_o)/(2). (iR^2)/((x^2 + R^2)^3//2))`
`=(4pixx10^(-7)xx5xx16xx10^(-4)/(2[((9xx16))xx10^(-4)] ^(3//2)`
`=(4pi xx80xx10^(-11)/(2xx125xx10^(-6)`
`=4.019xx10^(-5) T`
In downward direction. (b) N/A