Electric field at a place is $\vec E = {E_0}\hat i\,V/m$. A particle of charge $+q_0$ moves from point $A$ to $B$ along a circular path find work done in this motion by electric field
$\sqrt 2 \,{q_0}a{E_0}$
$\frac{{{q_0}a{E_0}}}{{\sqrt 2 }}$
${q_0}a{E_0}$
$2{q_0}{E_0}a$
A charge $q$ is placed at the centre of the line joining two equal charges $Q$. The system of the three charges will be in equilibrium, if $q$ is equal to
Two identical balls having like charges and placed at a certain distance apart repel each other with a certain force. They are brought in contact and then moved apart to distance equal to half their initial separation. The force of repulsion between them increases $4.5\,times$ in comparison with the initial value. The ratio of the initial charges of the balls is
Angle between equipotential surface and lines of force is.......$^o$
Three identical uncharged metal spheres are at the vertices of an equilateral triangle. One at a time, a small sphere is connected by a conducting wire with a large metal sphere that is charged. The center of the large sphere is in the straight line perpendicular to the plane of equilateral triangle and passing through its centre (see figure). As a result, the first small sphere acquires charge $q_1$ and second charge $q_2 (q_2 < q_1)$ . The charge that the third sphere $q_3$ will acquire is (Assume $l >> R$ , $l >> r$ , $d >> R$ , $d >> r$ )
Two identical parallel plate capacitor are placed in series and connected to a constant voltage source of $V_0\, volt$. If one of the capacitors is completely immersed in a liquid with dielectric constant $K$, the potential difference between the plates of the other capacitor will change to