Two parallel plate capacitors of capacitance C and 2C are connected in parallel and charged to a potential difference V by a battery. The battery is then C disconnected and the space between the plates of capacitor C is completely filled with a material of dielectric constant K. The potential difference across the capacitors now becomes:
Total original capacitance of system = C + 2C = 3C
if C is filled with delectric of K. dielectric constant K.
Then C' = KC
Now, capacitance of system C" = C' +2C = (K + 2) C
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