Two-point charges $a$ and $b,$ whose magnitudes are the same are positioned at a certain distance from each other with $a$ at the origin. The graph is drawn between electric field strength at points between $a$ and $b$ and distance $x$ from $a$. $E$ is taken positive if it is along the line joining from $a$ to $b$. From the graph, it can be decided that

 

A charged particle $‘q’$ is shot from a large distance with speed $v$ towards a fixed charged particle $Q$. It approaches $Q$ upto the closest distance $r$ and then returns. If $q$ were given a speed $‘2v’$, the closest distance of approach would be:

For an infinite line of charge having charge density $\lambda$ lying along $x$-axis, the work required in moving charge $q$ from $C$ to $A$ along arc $CA$ is:

Two short electric dipoles are placed as shown ($r$ is the distance between their centre). The energy of electric interaction between these dipoles will be

($C$ is centre of dipole of moment $P_2$)

A charge $q$ is placed at the centre of the cubical vessel (with one face open) as shown in the figure. The flux of the electric field through the surface of the vessel is

A dipole having a dipole moment $p$ is placed in front of a solid uncharged conducting sphere as shown in the diagram. The net potential at the point $A$ lying on the surface of the sphere is: