Using Gauss’ law, derive an expression for the electric field at a point near an infinitely long straight uniformly charged wire.

Options

A. r
B. `r^(2)`
C. `(1)/(r )`
D. `(1)/(r^(2))`

Answer

C

Explanation

The electric field due to an infinitely long straight uniformly charged wire at a distance r is
`E = (lambda)/(2pi epsilon_(0) r)` where `lambda` is the uniform linear charge density and `epsilon_(0)` is the permittivity of free space.
`E prop (1)/(r )`.