Question

Three point charges q, 2q and nq are placed at the vertices of an equilateral triangle. If the potential energy of the system is zero, find the value of n.

Two long straight wires 1 and 2 are kept as shown in the figure. The linear charge density of the two wires are λ₁ = 10 μC/m and λ₂ = − 20 μC/m. Find the net force F experienced by an electron held at point P.

Obtain the expression for the capacitance of a parallel plate capacitor with a dielectric medium between its plates.

A charge of 6 μC is given to a hollow metallic sphere of radius 0.2 m. Find the potential at (i) the surface and (ii) the centre of the sphere.

A charge + Q is placed on a thin conducting spherical shell of radius R. Use Gauss's theorem to derive an expression for the electric field at a point lying (i) inside and (ii) outside the shell.