Charges $+q$ and $-q$ are placed at points $A$ and $B$ respectively which are at distance $2\,L$ apart, $C$ is the midpoint between $A$ and $B$ . The work done in moving a charge $+ Q$ along the semicircle $CRD$ is
$ - \frac{{qQ}}{{6\pi \,{ \in _0}L}}$
$\frac{{qQ}}{{4\pi \,{ \in _0}L}}$
$\frac{{qQ}}{{2\pi \,{ \in _0}L}}$
$\frac{{qQ}}{{6\pi \,{ \in _0}L}}$
A parallel plate capacitor of capacitance $C$ is connected to a battery and is charged to a potential difference $V$ . Another capacitor of capacitance $2C$ is similarly charged to a potential difference $2V$ . The charging battery is now disconnected and the capacitors are connect 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
Charge of $2Q$ and $-Q$ are placed on two plates of a parallel plate capacitor if capacitance of capacitor is $C$ find potential difference between the plates
A charge $q$ is placed at the centre of cubical box of side a with top open. The flux of the electric field through one of the surface of the cubical box is
Three capacitors $1, 2$ and $4\,\mu F$ are connected in series to a $10\, volts$ source. The charge on the plates of middle capacitor is
Four capacitors with capacitances $C_1 = 1\,μF, C_2 = 1.5\, μF, C_3 = 2.5\, μF$ and $C_4 = 0.5\, μF$ are connected as shown and are connected to a $30\, volt$ source. The potential difference between points $B$ and $A$ is....$V$