Putting a dielectric substance between two plates of condenser: capacity, potential and potential energy, respectively 

A parallel plate capacitor of plate area $A,$ separation $d$ is filled with dielectrics as shown in the figure. The dielectric constants are $K_1$ and $K_2$. Net capacitance is, 

As shown in the figure half the space between plates of a capacitor is filled with an insulator material of dielectric constant $K,$ if initial capacity was $C$ then the new capacity is, 

Two materials of dielectric constant $k_1$ and $k_2$ are filled between two parallel plates of a capacitor as shown in the figure. The capacity of the capacitor is:

A parallel plate capacitor is filled with two dielectrics as shown in figure. If $A$ is area of each plate, then the effective capacitance between $X$ and $Y$ is

An insulator plate is passed between the plates of a capacitor. Then current