how will the capacity of a parallel plate capacitor be affected if any dielectric introduced between them has a considerable thickness....??

capacitance of a paralel palte cap is ε0A/d

if dielectric of thickness t is inserted then 

C= ε0A/(d-t+(t/K)) where K is diele const of material

hance capacity increses

Approved

it becomes,      C=area*permitivity constant/distance-thickness+thickness/dielectric constsnt

The dielectric between the plates passes a small amount of leakage current and also has an electric field strength limit, resulting in a breakdown voltage, while the conductors and leads introduce an undesired inductance and resistance.

The dielectric is just an electrical insulator. Examples of dielectric media are glass, air, paper, vacuum, and even a semiconductor depletion region chemically identical to the conductors. A capacitor is assumed to be self-contained and isolated, with no net electric charge and no influence from any external electric field. The conductors thus hold equal and opposite charges on their facing surfaces,^[10] and the dielectric develops an electric field.

A parallel plate capacitor can only store a finite amount of energy before dielectric breakdown occurs. The capacitor''s dielectric material has a dielectric strength U_d which sets the capacitor''s breakdown voltage at V = V_bd = U_dd.