Capacitor

A parallel plate capacitor has plate area '\(\mathrm{A}\)' and separation between plates is '\(d\)'. It is charged to a potential difference of \(\mathrm{V}_0\) volt. The charging battery is then disconnected and plates are pulled apart three times the initial distance. The work done to increase the distance between the plates is \(\left(\varepsilon_0=\right.\) permittivity of free space)