At steady state the charge on the capacitor, as shown in the circuit below, is _________ $\mu$C.

A capacitor of $$10 \mu \mathrm{F}$$ capacitance whose plates are separated by $$10 \mathrm{~mm}$$ through air and each plate has area $$4 \mathrm{~cm}^2$$ is now filled equally with two dielectric media of $$K_1=2, K_2=3$$ respectively as shown in figure. If new force between the plates is $$8 \mathrm{~N}$$. The supply voltage is ________ V.

The electric field between the two parallel plates of a capacitor of $$1.5 \mu \mathrm{F}$$ capacitance drops to one third of its initial value in $$6.6 \mu \mathrm{s}$$ when the plates are connected by a thin wire. The resistance of this wire is ________ $$\Omega$$. (Given, $$\log 3=1.1$$)

Three capacitors of capacitances $$25 \mu \mathrm{F}, 30 \mu \mathrm{F}$$ and $$45 \mu \mathrm{F}$$ are connected in parallel to a supply of $$100 \mathrm{~V}$$. Energy stored in the above combination is E. When these capacitors are connected in series to the same supply, the stored energy is $$\frac{9}{x} \mathrm{E}$$. The value of $$x$$ is _________.