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.

State Gauss's Law in electrostatics. Apply this to obtain the electric field E at a point near a uniformly charged infinite plane sheet.

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.

Consider a group of charges q₁, q₂, q₃ ... such that Σq ≠ 0. Then equipotentials at a large distance, due to this group are approximately :

Using Gauss's law, show that the electric field E→ at a point due to a uniformly charged infinite plane sheet is given by E→ = σ/(2ε₀) n̂ where symbols have their usual meanings.