Question

A parallel plate capacitor having area A and separated by distance d is filled by copper plate of thickness b. The new capacity is:

• A. $\frac{{\epsilon }_{0}A}{d+\frac{b}{2}}$
• B. $\frac{{\epsilon }_{0}A}{2d}$
• C. $\frac{{\epsilon }_{0}A}{d-b}$
• D. $\frac{{2\epsilon }_{0}A}{d+\frac{b}{2}}$

Answer 1

The correct option is C $\frac{{\epsilon }_{0}A}{d-b}$

Using Formula

$C^{\prime }=\frac{A{ϵ}_0}{((d-t)+\frac{t}{k})}$

where $A$ is the area of capacitor

$d$ is distance between plates of capacitor.

$t$ is the thickness of dielectric inserted between the plates .

$k$ is the dielectric constant.

Given $t=b$ and $k=\infty$, for copper plate

$C^{\prime }=\frac{A{ϵ}_0}{(d-b)}$

Hence option $\left(C\right)$ is correct