Question

A vector ${\overrightarrow{P}}_{1}$ is along the positive x-axis. If its vector product with another vector ${\overrightarrow{P}}_{2}$ is zero, then ${\overrightarrow{P}}_{2}$ could be–

• A. $4\widehat{j}$
• B. $- 4\widehat{i}$
• C. $(\widehat{j} + \widehat{k})$
• D. $- (\widehat{i} + \widehat{j})$

Answer 1

Answer: (B)

$- 4\widehat{i}$

Answer 2

$\overset{\rightarrow}{A} \times \overset{\rightarrow}{B}$ = AB sin q = 0

q = 0⁰ or 180⁰

so ${\overrightarrow{P}}_{2}$ = – 4$\widehat{i}$