A parallel plate air capacitor has capacity $C$, distance of separation between plates is $d$ and po

Question

A parallel plate air capacitor has capacity $C$, distance of separation between plates is $d$ and potential difference $V$ is applied between the plates. Force of attraction between the plates of the parallel plate air capacitor is

Professor PC Thomas Classes · Answer

Force of attraction between the plates of the parallel plate air capacitor is $F=\frac{Q^{2}}{2 \varepsilon_{0} A}$
where $Q$ is the charge on the capacitor, $\varepsilon_{0}$ is the permittivity of free space and $A$ is the area of each plate.
But $Q=C V$ and $C=\frac{\varepsilon_{0} A}{d}$ or $\varepsilon_{0} A=C d$
$	herefore \quad F=\frac{C^{2} V^{2}}{2 C d}=\frac{C V^{2}}{2 d}$