If potential at centre of uniformaly charged ring is $V_0$ then electric field at its centre will be (assume radius $=R$ )
$\frac{{{V_0}}}{R}$
$\frac{{{3V_0}}}{2R}$
$\frac{{{V_0}}}{2R}$
Zero
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
A capacitor $C = 100$ $ \mu F$ is connected to three resistors each of resistance $1$ $kW$ and a battery of emf $9$ $V$. The switch $S $ has been closed for long time so as to charge the capacitor. When switch $S $ is opened, the capacitor discharges with time constant.....$ms$
Potential in the $x-y$ plane is given as $V = 5(x^2 + xy)\, volts$. The electric field at the point $(1, -2)$ will be
Two conducting spheres of radii $r_1$ and $r_2$ have same electric fields near their surfaces. The ratio of their electric potentials is
Consider a system of there charges $\frac{q}{3},\,\frac{q}{3}$ and $-\frac{2q}{3}$ placed at point $A, B$ and $C,$ respectively, as shown in the figure. Take $O$ to be the centre of the circle of radius $R$ and $\angle CAB\, = \,{60^o}$