Question

Three rigid rods are joined to form an equilateral triangle ABC of side 1m. Three particles carrying charges 20μC each are attached to the vertices of the triangle. The whole system is at rest in an inertial frame. The resultant force on the charged particle at A has the magnitude

(a) zero

(b) 3.6N

(c) 3.6/3N

(d) 7.2N.

Answer 1

The correct answer is (a) zero

Explanation:

Since the charged particles are attached to rigid triangle ABC which is in rest in an inertial frame, so the particle at A is also at rest. It means the magnitude of resultant of forces acting on it is zero.