Question

Due to the flow of current in a circular loop of radius `R`, the magnetic induction produced at the centre of the loop is `B`. The magnetic moment of the loop is (`mu_(0)`=permeability constant)
A. `BR^(3)//2pi mu_(0)`
B. `2pi BR^(3)//mu_(0)`
C. `BR^(2)//2pi mu_(0)`
D. `2pi BR^(2)// mu_(0)`

Answer 1

Correct Answer - B
`B = (mu_(0)i)/(2R) rArr i = (2RB)/(mu_(0))`
`mu = iA = i.piR^(2) = (2RB)/(mu_(0)) xx pi R^(2) = (2pi BR^(3))/(mu_(0))`