A gaussian surface encloses three point charges \( q_1 = -14\,\mathrm{nC} \); \( q_2 = 78.85\,\mathrm{nC} \) and \( q_3 = -56\,\mathrm{nC} \). The electric flux for the gaussian surface due to these charges is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \( 1000\,\mathrm{N\,m^2\,C^{-1}} \)
By Gauss's law the flux through a closed surface depends only on the net charge enclosed.
\( \displaystyle \Phi = \frac{q_{\mathrm{enc}}}{\varepsilon_0} \)
\( \displaystyle q_{\mathrm{enc}} = -14 + 78.85 - 56 = 8.85\,\mathrm{nC} = 8.85\times10^{-9}\,\mathrm{C} \)
\( \displaystyle \Phi = \frac{8.85\times10^{-9}}{8.85\times10^{-12}} = 1000\,\mathrm{N\,m^2\,C^{-1}} \)
using \( \varepsilon_0 = 8.85\times10^{-12}\,\mathrm{C^2\,N^{-1}\,m^{-2}} \).