Four capacitors are connected in a circuit as shown in the figure. The effective capacitance in $\mu F$ between points $A$ and $B$ will be

$A$ parallel plate capacitor of capacitance $C$ is connected to a battery and charged to a potential difference $V$. Another capacitor of capacitance $3C$ is similarly charged to a potential difference $3V$. The charging battery is then disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energy of the configuration is

$A$ particle of mass $0.2 \ gm$ and charge $1 \ \mu C$ is held at a distance of $1 \ m$ from a fixed charge of $1 \ \mu C$. If the particle is released,it will be repelled. The speed of the particle when it is at a distance of $10 \ m$ from the fixed charge is $.... \ m/s$.

The charge on each capacitor when a voltage source of $15 \ V$ is connected in the circuit as shown,is (in $\mu C$)

Three identical capacitors, each of capacitance $C$, are connected in series, resulting in a net capacitance $x$. If these three capacitors are then connected in parallel, what is the ratio of the energy stored in the series configuration to the energy stored in the parallel configuration, assuming both configurations are connected to the same voltage source $V$?

Three capacitors are connected to a battery as shown in the figure. The ratio of charge on capacitors $C_3$ and $C_1$ is (in $.5$)