Q 12-01-016NEETJEE MainEasy
The electric field at a distance $r$ from an infinitely long straight wire with uniform linear charge density $\lambda$ is
Answer: (D) $\dfrac{\lambda}{2\pi\epsilon_0 r}$
Gauss's law with a coaxial cylinder of length $L$: $E(2\pi rL) = \dfrac{\lambda L}{\epsilon_0} \Rightarrow E = \dfrac{\lambda}{2\pi\epsilon_0 r}$.
Solution by Sreeraj P, M.Sc Physics