Q. The radius vector and linear momentum are respectively given by vector 2$\widehat{i} + 2\widehat{j} + \widehat{k}$ and 2$\widehat{i} - 2\widehat{j} + \widehat{k}$. Their angular momentum is
A) $2\widehat{i} - 4\widehat{j}$
B) $4\widehat{i} - 8\widehat{k}$
C) 2$\widehat{i} - 4\widehat{j} + 2\widehat{k}$
D) 4$\widehat{i} - 8\widehat{j}$
Explanation
(b) Angular momentum $\overrightarrow{L} = \overrightarrow{r} \times \overrightarrow{p}$
$= \left( 2\widehat{i} + 2\widehat{j} + \widehat{k} \right) \times \left( 2\widehat{i} - 2\widehat{j} + \widehat{k} \right) = 4\widehat{i} - 8\widehat{k}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.