Q. What is the unit vector along $\widehat{i} + \widehat{j}?$
A) $\frac{\widehat{i} + \widehat{j}}{\sqrt{2}}$
B) $\sqrt{2}(\widehat{i} + \widehat{j})$
C) $\widehat{i} + \widehat{j}$
D) $\widehat{k}$
Explanation
(a) $\overrightarrow{A} = A\overrightarrow{A}$ or $\overrightarrow{A} = \frac{\overrightarrow{A}}{A}$
$\therefore$ required unit vector is $\frac{\widehat{i} + \widehat{j}}{\left| \widehat{i} + \widehat{j} \right|} = \frac{\widehat{i} + \widehat{j}}{\sqrt{2}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.