Question

Electric field outside a long wire carrying charge q is proportional to

• A. $\frac{1}{r}$
• B. $\frac{1}{r^2}$
• C. $\frac{1}{r{}^3/5}$
• D. $\frac{1}{r{}^3/2}$

Answer 1

Answer: (A)

Electric field due to a long charged wire is given as
$E=\frac{\lambda }{2\pi {\in }_{0}r}$
where, $\lambda =$ linear charge density.
$r=$ distance from the wire.
$\therefore E\infty \frac{1}{r}$