Question

Electric field due to infinite, straight uniformly charged wire varies with distance '$r$' as

• A. $r$
• B. $\frac{1}{r}$
• C. $\frac{1}{r^2}$
• D. $r^2$

Answer 1

Answer: (B)

$\vec{E}=\frac{1}{4\pi {\epsilon }_0}\frac{2\lambda }{r}$
(or) $\vec{E}=\frac{\lambda }{2\pi {\epsilon }_{0}r}\hat{r}$
$\Rightarrow |\vec{E}|\propto \frac{1}{r}$