An infinitly long wire is charged uniformly with charge density $\lambda$ and placed in air, the electric field at distance r from wire will be:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → $\frac{\lambda}{2 \pi \varepsilon_0 r}$
Using Gauss's law,
$\vec E=\frac{\lambda}{2 \pi \varepsilon_0 r}$
where,
$\lambda$ = linear charge density.
$r$ = Distance