Find the magnetic moment of a thin round loop with current if the radius of the loop is equal to `R = 100 mm` and the magnetic induction at its centre is equal to `B = 6.0 mu T`.

Explanation

Magnetic moment of a current loop is given `P_(m) = niS` (where `n` is the number of turns and `S`, the current sectional area.) In our problem, `n = 1, S = pi R^(2)` and `B = (mu_(0))/(2) (i)/(R)`
`P_(m) = (2 B R)/(mu_(0)) pi R^(2) = (2pi B R^(3))/(mu_(0))`