Question

Two charges A (charge q) and B (charge 2q) are located at points (0, 0) and (a, a) respectively. Let î and ĵ be the unit vectors along x-axis and y-axis respectively. Find the force exerted by A on B, in terms of î and ĵ.

Two charges q₁ and q₂ are placed at the centres of two spherical conducting shells of radius r₁ and r₂ respectively. The shells are arranged such that their centres are d [> (r₁ + r₂)] distance apart. The force on q₂ due to q₁ is :

Coulomb force F versus 1/r² graphs for two pairs of point charges (q₁ and q₂) and (q₂ and q₃) are shown in the figure. The ratio of charges q₁/q₃ is :

Three small charged spheres X, Y and Z carrying charges + q, – q and + q respectively are placed equidistant from each other, as shown in the figure. The spheres Y and Z are held in place. Initially X is also held in place, but is otherwise free to move. When X is released, the path followed by it will be :