Q 12-02-089JEE MainJEE Main 2023 (24 Jan, Shift 2)Easy
A parallel plate capacitor with air between the plates has a capacitance of $15\ \text{pF}$. The separation between the plates becomes twice and the space between them is filled with a medium of dielectric constant $3.5$. Then the capacitance becomes $\dfrac x4$ pF. The value of $x$ is ______.
Numerical value type. Enter your answer.
Answer: 105
$C'=\dfrac{K\epsilon_0A}{2d}=\dfrac{3.5}{2}\times15=26.25\ \text{pF}=\dfrac{105}{4}\ \text{pF}$. So $x=105$.
Solution by Sreeraj P, M.Sc Physics