The outer sphere of a spherical air capacitor is earthed. For increasing its capacitance,

A parallel plate capacitor is charged and then disconnected from the charging battery. If the plates are now moved farther apart by pulling them by means of insulating handles, then

A parallel plate capacitor is charged and then isolated. The effect of increasing the plate separation on charge, potential and capacitance respectively are 

The respective radii of the two spheres of a spherical condenser are $12 \mathrm{cm}$ and $9 \mathrm{cm}$. The dielectric constant of the medium between them is $6$. The capacity of the condenser will be

The capacity of a parallel plate condenser is $15 \mu \mathrm{F}$ when the distance between its plates is $6 \mathrm{cm}$. If the distance between the plates is reduced to $2 \mathrm{cm}$, then the capacity of this parallel plate condenser will be 

A parallel plate capacitor of $6 \mu \mathrm{F}$ is connected across $18 \mathrm{V}$ battery and charged. The battery is then disconnected and oil of dielectric constant $\mathrm{k}=2.1$ is introduced between the plates. What will be the charge on capacitor? 

The capacity of a parallel plate condenser is $12 \mu \mathrm{F}$. Its capacity, when the separation between plates is doubled and area is halved will be

A cylindrical capacitor has charge $Q$ and length $L$. If both the charge and length of the capacitor are doubled by keeping other parameters fixed, the energy stored in the capacitor 

Consider the situation shown in the figure. The capacitor $A$ has a charge $q$ on it whereas $B$ is uncharged. The charge appearing on the capacitor $B$ a long time after the switch is closed is