# A point charge causes and electric flux $-3 × 10^{14} N-m^2 /C$ to pass through a spherical Gaussian surface Calculate the value of the point charge.

By Gauss’s theorem, total electric flux through closed Gaussian surface
$\phi =\large\frac{q}{\in _0}$
$q= \phi \in_0$
But electric flux passing through the surface
$\phi =-3 \times 10^{-14} N -m^2/C$
$q= (-3 \times 10^{-14} ) \times 8.85 \times 10^{-12}$
$\quad= -26.55 \times ^{-25} \;C$
$\quad= -2.655 \times 10^{-25}$
Hence B is the correct answer.