Question

A charged particle (charge `q`) is moving in a circle of radius `R` with unifrom speed `v`. The associated magnetic moment `mu` is given by
A. `(qvR)/(2)`
B. `qvR^(2)`
C. `(qvR^(2))/(2)`
D. `qvR`

Answer 1

Correct Answer - A
As revolving charge is equivalent to a current, so
`I = af = q xx (omega)/(2pi)`
But `omega = (v)/(R )`
where `R` is radius of circle and `v` is unifrom speed of charged particle.
Therefore, `I = (qv)/(2pi R)`
Now, magetic moment associated with charged particles is given by
`mu = IA = I xx pi R^(2)`
or `mu = (qv)/(2piR) xx piR^(2) = (1)/(2)qvR`