Consider the situation shown. The switch $S$ is opened for a long time and then closed. The charge flown through the battery when $S$ is closed

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....$V$

Four point $+ve$ charges of same magnitude $(Q)$ are placed at four corners of a rigid square frame in $xy$ plane as shown in figure. The plane of the frame is perpendicular to $z-$ axis. If a $-ve$ point charges is placed at a distance $z$ away from the above frame $(z << L)$ then

A $2\,\mu F$ capacitor is charged to a potential $=10\ V$ . Another $4\,\mu F$ capacitor is charged to a potential $= 20\ V$ . The two capacitors are then connected in a single loop, with the positive plate of one connected with negative plate of the other. What heat is evolved in the circuit ?.........$\mu J$

A charg $Q$ is divided into two parts $q$ and $Q-q$ and separated by a distance $R$ . The force of repulsion between them will be maximum when

A wheel having mass $m$ has charges $+q$ and $-q$ on diametrically opposite points. It  remains in equilibrium on a rough inclined plane in the presence of uniform horizontal  electric field $E =$