Question
A slab of material of dielectric constant K has the same area as that of the plates of a parallel plate capacitor but has the thickness d/2, where d is the separation between the plates. Find out the expression for its capacitance when the slab is inserted between the plates of the capacitor.
Solution
Capacitance having a dielectric of thickness ‘t’ is given by,
When the thickness of the plates is reduced to half, t = d/2 then,
Capacitance becomes, 
