$A$ parallel plate capacitor is charged fully by using a battery. Then,without disconnecting the battery,the plates are moved further apart. Then,

Four identical capacitors and three identical resistors are connected to a battery with $emf$ $E$ and internal resistance $r$ as shown in the figure. Find the charge on each capacitor.

In the given capacitive network,the resultant capacitance between points $A$ and $B$ is: (in $\mu F$)

Assertion: Charges are given to plates of two plane parallel plate capacitors $C_1$ and $C_2$ (such that $C_2 = 2C_1$) as shown in the figure. Then the key $K$ is pressed to complete the circuit. Finally,the net charge on the upper plate and the net charge on the lower plate of capacitor $C_1$ is positive.
Reason: In a parallel plate capacitor,both plates always carry equal and opposite charge.

Find the potentials at points $A$ and $B$ in the circuit shown in the figure.

As shown in the figure,the work done in moving a charge $q$ from $A$ to $B$ and from $B$ to $C$ is $2 \ J$ and $-3 \ J$ respectively. The work done in moving the charge from $C$ to $A$ will be ...... $J$.