question_answer

Figure below shows regular hexagon, the charges are placed at the vertices. In which of the following cases the electric field at the centre is zero?

A)

B)

C)

D)

Correct Answer: D

Solution :

                 The intensity of electric field (E) due to charge (q) placed at a distance (r) is given by                 \[E=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{q}{r}\]                 In Fig. II as is evident the electric field (E) due to opposite charges cancel each other. The field due to charge at B and E are equal and opposite, hence cancel out, similarly due to A and D, and due to D and C. Therefore, resultant field is zero.