Question

For the given semi-infinite rod of uniformly distributed line charge, angle $\left(\theta \right)$ between net electric field and component of net electric field perpendicular to the axis of line charge at the point $\text{P}$ is

• A. ${30}^{\circ }$
• B. ${45}^{\circ }$
• C. ${60}^{\circ }$
• D. ${15}^{\circ }$

Answer 1

The correct option is B ${45}^{\circ }$


We know that, electric field due to semi-infinite rod of uniformly distributed line charge is given as

$|{\overrightarrow{E}}_{\text{II}}|=|{\overrightarrow{E}}_{\perp }|=\frac{k\lambda }{r}$

Thus, $\tan \theta =\frac{|{\overrightarrow{E}}_{\text{II}}|}{|{\overrightarrow{E}}_{\perp }|}=1$

$\Rightarrow \theta ={\tan }^{-1}\left(1\right)={45}^{\circ }$

Hence, option $\left(c\right)$ is correct.