Question

The electric flux for Gaussian surface $A$ that encloses the charged particles in free space is (Given: $q_{1}=-14 \,nC$ $\left.q_{2}=78.85\, nC , q_{3}=-56 \,nC \right)$

• A. $10^{3} N m ^{2} C ^{-1}$
• B. $10^{3} C N ^{-1} m ^{-2}$
• C. $6.32 \times 10^{3} N m ^{2} C ^{-1}$
• D. $6.32 \times 10^{3} C N ^{-1} m ^{-2}$

Answer 1

Answer: (A)

Flux is due to charges enclosed by the given surface.
$\therefore $ Total flux $=(-14+78.85-56) nC / \varepsilon_{0}$
$=8.85 \times 10^{-9} C \times \frac{4 \pi}{4 \pi \varepsilon_{0}}=8.85 \times 10^{-9} \times 9 \times 10^{9} \times 4 \pi$
$=1000.4 \,Nm ^{2} / C$ i..e. $1000 \,Nm ^{2} C ^{-1}$