Question

A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment $\mu$ is given by

• A. $qvR$
• B. $qv\frac{R}{2}$
• C. $qv{R}^2$
• D. $qv\frac{R^2}{2}$

Answer 1

Answer: (B)

$qv\frac{R}{2}$

The current in circular path due to movement in circle is given by

$i=\frac{q}{T}=\frac{qv}{2\pi R}$

Hence the magnetic moment associated with the particle is

$\mu =iA=\frac{qv}{2\pi R}\pi R^2$

$=\frac{qvR}{2}$