A square plate of side $'a'$ is placed in $xy$ plane having centre at origin if charge density of square plate is $\sigma = xy$ then. Total charge on the plate will be.

Two capacitor one of capacitance $C$ and other capacitance $C/2$ are connected with a battery of $V$ $volt$ then heat produced in connecting wire

Four capacitors of capacitance $10\, \mu\, F$ and a battery of $200\,V$ are arranged as shown.  How much charge will flow through $AB$ after the switch $S$ is closed?

In the circuit, shown in the figure, the effective capacitance between $A$ and $B$ is......$\mu F$

Two identical small spheres carry charge of $Q_1$ and $Q_2$ with $Q_1>>Q_2.$ The charges are $d$ distance apart. The force they exert on one another is $F_1.$ The spheres are made to touch one another and then separated to distance $d$ apart. The force they exert on one another now is $F_2.$ Then $F_1/F_2$ is

A parallel plate capacitor with air between the plates has a capacitance of $9\ pF$. The separation between its plates is '$d$'. The space between the plates is now filled with two dielectrics. One of the dielectric has dielectric constant $K_1 = 6$ and thickness $\frac{d}{3}$ while the other one has dielectric constant $K_2 = 12$ and thickness $\frac{2d}{3}$. Capacitance of the capacitor is now........$pF$