Q. A particle with position vector $r$ has a linear momentum $p$. Which of the following statements is true in respect of its angular momentum $L$ about the origin
A) $L$ acts along $p$
B) $L$ acts along $r$
C) $L$ is maximum when $p$ and $r$ are parallel
D) $L$ is maximum when $p$ is perpendicular to $r$
Explanation
(d) Angular momentum $L$ is given as
$L = \overrightarrow{r} \times \overrightarrow{p} = rp\sin\theta$
$\overrightarrow{r} =$ position vector of the particle $w.r.t.$ origin,
$\overrightarrow{p} =$ its linear momentum
$\overrightarrow{r} \times \overrightarrow{p}$ is maximum when $p$ is perpendicular to $r$
$i.e.\ \theta = 90{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.