Under steady state condition the potential difference across the capacitor in the circuit is $\_\_\_\_$ V.

From the circuit given below, the capacitance between terminals $A$ and $B$ shown in the circuit is $\_\_\_\_$ $\mu \mathrm{F}$.

(take $C_1=C_2=C_3=1 \mu \mathrm{~F}$ and $C_4=2 \mu \mathrm{~F}$.)

A parallel plate air capacitor is connected to a battery. The plates are pulled apart at uniform speed $v$. If $x$ is the separation between the plates at any instant, then the time rate of change of electrostatic energy of the capacitor is proportional to $x^\alpha$, where $\alpha$ is $\_\_\_\_$ .

A parallel plate air capacitor has a capacitance $C$. When it is half filled as shown in figure with a dielectric constant $K = 5$, the percentage increase in the capacitance is ________.