Consider a small cube of volume `1 mm ^3` at the centre of a circular loop of radius 10 cm carrying a current of 4 A. Find the magnetic energy stored inside the cube.

Explanation

Energy density `=(B^2)/(2(mu_0))`
Total energy stored =(B^(2)V)/(2(mu_0))`
`=(4 pixx10^(-7)xx(4)^2xx1xx10^(-9))/(4xx10^(2)xx2)`
`=8 pixx10^(10^(-14) J.`