Q148 / 180 · COMEDK 2025 (10 May Shift 2) · Physics
When a dielectric slab of dielectric constant $\mathrm{k}=2$ is used to fill the space between the plates of a parallel plate capacitor, the capacitance of the capacitor is found to be $20 \mu \mathrm{F}$. What will be the capacitance when the slab is replaced with air?
- A$40 \mu F$
- B$20 \mu F$
- C$5 \mu F$
- Correct answerD$10 \mu F$
Solution
The capacitance of a parallel plate capacitor filled with a dielectric material is given by the formula $C = K C_0$, where $C$ is the capacitance with the dielectric, $K$ is the dielectric constant, and $C_0$ is the capacitance with air as the medium.
Given $C = 20 \mu F$ and $K = 2$, we substitute these values into the equation:
$20 \mu F = 2 \times C_0$
Solving for $C_0$:
$C_0 = \dfrac{20 \mu F}{2} = 10 \mu F$.
Answer: $10 \mu F$
Given $C = 20 \mu F$ and $K = 2$, we substitute these values into the equation:
$20 \mu F = 2 \times C_0$
Solving for $C_0$:
$C_0 = \dfrac{20 \mu F}{2} = 10 \mu F$.
Answer: $10 \mu F$
Hence, the correct answer is option: 'D'.