Question

A unit vector in $XY-$plane, making an angle of ${30}^o$ in anti-clockwise direction with the positive direction of $X-$axis is

• A. $\frac{1}{2}\hat{i}+\frac{3}{2}\hat{i}$
• B. $4\hat{i}+3\hat{j}$
• C. $4\frac{\sqrt{3}}{2}\hat{i}+\hat{j}$
• D. $\frac{\sqrt{3}}{2}\hat{i}+\frac{1}{2}\hat{j}$

Answer 1

The correct option is D $\frac{\sqrt{3}}{2}\hat{i}+\frac{1}{2}\hat{j}$

$vecr=\cos {30}^{\circ }\hat{ı}+\sin {30}^{\circ }\hat{j}$

$=\frac{\sqrt{3}}{2}\hat{ı}+\frac{1}{2}\hat{ȷ}$