Two conducting shells of radius $a$ and $b$ are connected by conducting wire as shown in figure. The capacity of system is :

Two spherical conductors $A$ and $B$ of radii $a$ and $b$ $(b > a)$ are placed concentrically in air. The two are connected by a copper wire as shown in figure. Then the equivalent capacitance of the system is

A condenser of $2\,\mu F$ capacitance is charged steadily from $0$ to $5$ $Coulomb$. Which of the following graphs correctly represents the variation of potential difference across its plates with respect to the charge on the condenser

Two metal spheres of capacitance ${C_1}$ and ${C_2}$ carry some charges. They are put in contact and then separated. The final charges ${Q_1}$ and ${Q_2}$ on them will satisfy

Assertion : The total charge stored in a capacitor is zero.

Reason : The field just outside the capacitor is $\frac{\sigma }{{{\varepsilon _0}}}$. ( $\sigma $ is the charge density).

When we touch the terminals of a high voltage capacitor, even after a high voltage has been cut off, then the capacitor has a tendency to