Shown in the figure are two point charges $+Q$ and $-Q$ inside the cavity of a spherical shell. The charges are kept near the surface of the cavity on opposite sides of the centre of the shell. If ${\sigma }_1$ is the surface charge on the inner surface and $Q_1$ net charge on it and ${\sigma }_2$ the surface charge on the outer surface and $Q_2$ net charge on it then:

Arrangement of charges are shown in the figure. Flux linked with the closed surface $P$ and $Q$ respectively are ________ and ________ .

A parallel plate capacitor having plates of area $S$ and plate separation $d$, has the capacitance $C_1$ in air. When two dielectrics of different relative permittivity $\left({\epsilon }_1=2 \text{and} {\epsilon }_2=4\right)$ are introduced between the two plates as shown in the figure, the capacitance becomes $C_2$. The ratio $\frac{C_2}{C_1}$ is, 

In the figure is shown a system of four capacitors connected across a $10 \mathrm{V}$ battery. The charge that will flow from switch S when it is closed is:

In the figure, a capacitor is filled with dielectrics. The resultant capacitance is

The effective capacity in the following figure between the points $P$ and $Q$ will be 

For section $AB$ of a circuit shown in figure, $C_1=1 \mathrm{\mu F},C_2=2 \mathrm{\mu F},E=10 \mathrm{V}$, and the potential difference $V_A-V_B=-10 V$. Charge on capacitor $C_1$ is:

Figure shows a network of capacitors where the number indicates capacitances in micro Farad. The value of capacitance C if the equivalent capacitance between point A and B is to be $1 \mu F$ is :