Question

A cylinder of radius $r$ and length $l$ is placed in an uniform electric field in such a way that the axis of the cylinder is parallel to the field. The flux of the field through the cylindrical surface is

• A. $\frac{2 r l}{\varepsilon_{0}}$
• B. $\frac{l}{\varepsilon_{0}}$
• C. $\frac{2 \pi r l}{\varepsilon_{0}}$
• D. zero

Answer 1

Answer: (D)

$\Delta \vec{S}$ on cylindrical surface is perpendicular to $\vec{E}$.
$\therefore$ $\Sigma \vec{E} \cdot \Delta \vec{S}=0$