A capacitor has air as dielectric medium and two conducting plates of area 12 ~cm^2 and they are 0.6 ~cm apart. When a slab of dielectric having area 12 ~cm^2 and 0.6 ~cm thickness is inserted between the plates, one of

Correct answer: D. 1.50 aligned & A _ o d = A _ o (0.2+ d k ) & 0.6=0.2+ 0.6 k & k=(3)/(2) aligned

JEE Main 20248 AprilEvening Shift

JEE Main 2024 · 8 April · Evening Shift · Physics · Capacitance

A capacitor has air as dielectric medium and two conducting plates...

A capacitor has air as dielectric medium and two conducting plates of area

12 \mathrm{~cm}^2

and they are

0.6 \mathrm{~cm}

apart. When a slab of dielectric having area

12 \mathrm{~cm}^2

and

0.6 \mathrm{~cm}

thickness is inserted between the plates, one of the conducting plates has to be moved by

0.2 \mathrm{~cm}

to keep the capacitance same as in previous case. The dielectric constant of the slab is : (Given

\epsilon_0=8.834 \times 10^{-12} \mathrm{~F} / \mathrm{m}

)

D. $1.50$

\begin{aligned} & \frac{\mathrm{A} \varepsilon_{\mathrm{o}}}{\mathrm{d}}=\frac{\mathrm{A} \varepsilon_{\mathrm{o}}}{\left(0.2+\frac{\mathrm{d}}{\mathrm{k}}\right)} \\ & 0.6=0.2+\frac{0.6}{\mathrm{k}} \\ & \mathrm{k}=\frac{3}{2}\end{aligned}