Consider a cube of uniform charge density $\rho$. The ratio of electrostatic potential at the centre of the cube to that at one of the corners of the cube is
$2$
$\sqrt{3} / 2$
$\sqrt{2}$
$1$
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 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 $E =$
Electric field at a point varies as $r^o$ for
The work done required to put the four charges together at the corners of a square of side $a$ , as shown in the figure is
The electric potential $V$ at any point $(x, y, z)$ (all in $metres$ ) in space is given by $V = 4x^2\, volt$. The electric field at the point $(1\, m, 0, 2\, m)$ in $volt/metre$ is