Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If the electric flux entering and leaving an enclosed surface respectively is $\phi_1$ and $\phi_2$, the electric charge inside the surface will be
PhysicsElectrostaticsJEE MainJEE Main 2003
Options:
  • A
    $\left(\phi_2-\phi_1\right) \varepsilon_0$
  • B
    $\left(\phi_1+\phi_2\right) / \varepsilon_0$
  • C
    $\left(\phi_2-\phi_1\right) / \varepsilon_0$
  • D
    $\left(\phi_1+\phi_2\right) \varepsilon_0$
Solution:
1424 Upvotes Verified Answer
The correct answer is:
$\left(\phi_2-\phi_1\right) \varepsilon_0$
According to Gauss's Law
$$
\begin{aligned}
& \int(\text { E.dA })=\mathrm{q}_0 / \varepsilon_0 \Rightarrow \mathrm{q}=\varepsilon_0\left(\phi_2-\phi_1\right) \\
& {\left[\text { since } \phi=\int \mathrm{E} \cdot \mathrm{dA}\right]}
\end{aligned}
$$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.