Question

Figure in column 1 shows some fixed charge systems $(+Q/-Q)$ and movable point charge $(q/-q)$, match the options in column 1 for equilibrium of $(q/-q)$ in the given direction.

Answer 1

For (A), if the we moves the +q charge in the y-direction, it can not return to its equilibrium position due to the repulsion force between charges +Q and +Q. It is an unstable system.

For (B), when +q is moved from its equilibrium position along the x-direction, it returns back its equilibrium position due to the repulsion forces between (+Q,+q) and(+q,+Q). It is in stable condition.

For (C), if +q slightly displaced from its position it stills remain in equilibrium. so it is in the neutral condition.

For (D), in this case +q charge is accelerating along x - axis due to the attraction force between (-q,+Q) and the repulsion force between (+Q,+q).

For (E),if we move the charge q,its again return back to its equilibrium due to the attraction force between (+Q,-q) .so it is in stable equilibrium.

Ans : $A\to 1,B\to 3,C\to 4,D\to 2,E\to 3.$