A point charge q is placed at the centre of the hemispherical surface of radius. The flux through the hemispherical surface is:

$\frac{q}{2 \epsilon_0}$

The correct answer is Option (2) → $\frac{q}{2 \epsilon_0}$

The electric flux through the spherical surface can be calculated using Gauss law-

$\phi_{sphere}=\frac{q_{enclosed}}{ε_0}=\frac{q}{ε_0}$ [Gauss law]

$⇒\phi_{hemisphere}=\frac{1}{2}\frac{q}{ε_0}=\frac{q}{2ε_0}$