A gaussian surface encloses three point charges $q_1 = -14 nC ; q_2 = 78.85 nC$ and $q_3=-56 nC$. The electric flux for the gaussian surface due to these charges is

$1000\, Nm^2\, C^{-1}$

The correct answer is Option (1) → $1000\, Nm^2\, C^{-1}$

According to Gauss's law, the total electric flux through a closed surface:

$\Phi_E = \frac{Q_{\text{enclosed}}}{\varepsilon_0}$

Total charge enclosed:

$Q_{\text{enclosed}} = q_1 + q_2 + q_3 = (-14 + 78.85 - 56)\ \text{nC} = 8.85\ \text{nC} = 8.85 \times 10^{-9}\ \text{C}$

Electric flux:

$\Phi_E = \frac{8.85 \times 10^{-9}}{8.85 \times 10^{-12}} = 10^3 \ \text{Nm}^2/\text{C}$

Electric flux through the Gaussian surface = $1.0 \times 10^3 \ \text{Nm}^2/\text{C}$