As shown in figure charges +q, +q, -q and -q are placed on the vertices of square, each side length is 2l. The electric potential at mid-point ‘A’ of charges +q and +q is .

Question

Accepted Answer

(4) (2kq)/l[1-1/(√5)]. Given: a square of side 2l with +q at the two ends of the left side and -q at the other two corners; A is the mid-point of the side joining the +q charges, so the figure marks l from the top-left corner down to A and 2l for the full side. Idea: add the four potentials as signed scalars, V=Σ(kqᵢ)/(rᵢ). Each +q is l from A: together they give 2×(kq)/l. Each -q is across the square: r=√(2l)²+l²=√5 l, so together they give -2×(kq)/(√5 l). V_A=(2kq)/l-(2kq)/(√5 l)=(2kq)/l[1-1/(√5)].

As shown in figure charges +q, +q, -q and -q are placed on the vertices of square, each side length is 2l. The electric potential at mid-point ‘A’ of charges +q and +q is ________.

Step-by-step solution

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