A point charge -5 μC is at a distance 5 cm directly above the centre of a square of side 10 cm. The magnitude of electric flux through this square is

$\frac{5×10^{-6}}{6ε_0}NC^{-1} m^2$

The correct answer is Option (4) → $\frac{5×10^{-6}}{6ε_0}NC^{-1} m^2$

Using Gauss's law,

$\phi_{total}=\frac{q_{enc}}{ε_0}$

flux through the square (one face),

$\phi_{square}=\frac{1}{6}\frac{q}{ε_0}$

$∴\phi_{square}=\frac{1}{6}\frac{5×10^{-6}}{ε_0}NC^{-1} m^2$