Question

Given :$\overrightarrow{A} = \widehat{i} + 2\widehat{j} - 3\widehat{k}$. When a vector $\overrightarrow{B}$ is added to $\overrightarrow{A}$, we get a unit vector along X-axis. Then, $\overrightarrow{B}$ is–

• A. $- 2\widehat{j} + 3\widehat{k}$
• B. $- \widehat{i} - 2\widehat{j}$
• C. $- \widehat{i} + 3\widehat{k}$
• D. $2\widehat{j} - 3\widehat{k}$

Answer 1

Answer: (A)

$- 2\widehat{j} + 3\widehat{k}$

Answer 2

$\overset{\rightarrow}{B}$ + ($\widehat{i}$ + 2$\widehat{j}$ – 3$\widehat{k}$) = $\widehat{i}$

$\overset{\rightarrow}{B}$ = – 2$\widehat{j}$ + 3$\widehat{k}$