JEE Physics · Hard

Electrostatics: Coulomb's Law MCQ

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Coulomb's LawHardQuestion 31468

Question

Three charges +q, +q, −q are placed at (0,0), (d,0), (d/2,d√3/2) — equilateral triangle. Net force on −q:
  1. A
    √3kq²/d²
    Correct
  2. B
    kq²/d²
  3. C
    2kq²/d²
  4. D
    Zero

Correct answer

√3kq²/d²

Explanation

Each +q exerts kq²/d² on −q. By vector addition (120° between them): F_net = √3×kq²/d² directed toward midpoint of the two +q charges.