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
Two parallel plates with dielectric placed between the plates are as shown in figure. The resultant capacity of capacitor will [A = area of plate. $t_1, t_2$ and $t_3$ are thickness of dielectric slabs, $k_1$, $\mathrm{k}_2$ and $\mathrm{k}_3$ are dielectric constant.]

PhysicsCapacitanceMHT CETMHT CET 2021 (23 Sep Shift 2)
Options:
  • A $\frac{\mathrm{A} \varepsilon_0}{\left[\frac{\mathrm{t}_1+\mathrm{t}_2+\mathrm{t}_3}{\mathrm{k}_1+\mathrm{k}_2+\mathrm{k}_3}\right]}$
  • B $\frac{\mathrm{A} \varepsilon_0\left(\mathrm{k}_1 \mathrm{k}_2 \mathrm{k}_3\right)}{\mathrm{t}_1 \mathrm{t}_2 \mathrm{t}_3}$
  • C $\mathrm{~A} \varepsilon_0\left[\frac{\mathrm{k}_1}{\mathrm{t}_1}+\frac{\mathrm{k}_2}{\mathrm{t}_2}+\frac{\mathrm{k}_3}{\mathrm{t}_3}\right]$
  • D $\frac{\mathrm{A} \varepsilon_0}{\left[\frac{\mathrm{t}_1}{\mathrm{k}_1}+\frac{\mathrm{t}_2}{\mathrm{k}_2}+\frac{\mathrm{t}_3}{\mathrm{k}_3}\right]}$
Solution:
2931 Upvotes Verified Answer
The correct answer is: $\frac{\mathrm{A} \varepsilon_0}{\left[\frac{\mathrm{t}_1}{\mathrm{k}_1}+\frac{\mathrm{t}_2}{\mathrm{k}_2}+\frac{\mathrm{t}_3}{\mathrm{k}_3}\right]}$
These are three capacitors connected in series.
$$
\begin{aligned}
& \frac{1}{\mathrm{C}}=\frac{1}{\mathrm{C}_1}+\frac{1}{\mathrm{C}_2}+\frac{1}{\mathrm{C}_3}=\frac{\mathrm{t}_1}{\varepsilon_0 \mathrm{Ak}_1}+\frac{\mathrm{t}_2}{\varepsilon_0 \mathrm{Ak}_2}+\frac{\mathrm{t}_3}{\varepsilon_0 \mathrm{Ak}_3} \\
& \mathrm{C}=\frac{\mathrm{A} \varepsilon_0}{\left[\frac{\mathrm{t}_1}{\mathrm{k}_1}+\frac{\mathrm{t}_2}{\mathrm{k}_2}+\frac{\mathrm{t}_3}{\mathrm{k}_3}\right]}
\end{aligned}
$$

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.