Question

Two point charges +3 nc and -3nc are placed at the corners a and b of an equilateral triangle abc of side 0.3m in air.If a charge +2nc is placed at the point c what is the force acting on it

Answer 1

Two point charges +3 nc and -3nc are placed at the corners A and B of an equilateral triangle abc of side 0.3m in air. A charge +2nc is placed at the point C as shown in figure.

magnitude of force between A and C , F = k(3nC)(2nC)/(0.3m)²

= 9 × 10^9 × (3 × 10^-9) × (2 × 10^-9)/0.09

= 10¹¹ × 6 × 10^-18

= 6 × 10^-7 N

and magnitude of force between A and C , F = 6 × 10^-7 N

it is clearly shown that angle between both forces is 120°

now, resultant force = √{F² + F² + 2F²cos120°}

= F = 6 × 10^-7 N

hence, net force acting on it is 6 × 10^-7 N