Question

A particle of charge $q$ and mass $m$ moves in a circular path of radius $r$ in a uniform magnetic field $B$.
The angular momentum of the particle can be described by the expression:

• A. $eBr$
• B. $2eBr$
• C. $eB{r}^2$
• D. $eBr{m}_p$
• E. $2eBr{m}_p$

Answer 1

Answer: (C)

$eB{r}^2$

Angular momentum of the particle $L=mvr$

Using $eBr=mv$

$⟹$ $L=\left(eBr\right)r=eB{r}^2$