A parallel plate air capacitor is charged upto 100 V. A plate 2 mm thick is inserted between the plates. Then to maintain the same potential difference, the distance between the plates is increased by 1.6 mm. The dielectric constant of the thick plate is

A parallel plate capacitor filled with oil of a dielectric constant 3 between the plates has capacitance 'C'. If the oil is removed, then the capacitance of the capacitor will be

Two capacitors of capacities $2 \mu \mathrm{~F}$ and $4 \mu \mathrm{~F}$ are connected in parallel. A third capacitor of $6 \mu \mathrm{~F}$ capacity is connected in series with this combination. A battery of 12 V is connected across this combination. The charge on $2 \mu \mathrm{~F}$ capacitor is

Five capacitors each of capacity $$C$$ are connected as shown in figure. If their resultant capacity is $$2 \mu \mathrm{F}$$, then the capacity of each condenser is