Two point charges of 1 nC and 2 nC are placed at the two corners of equilateral triangle of side 3 cm. The work done in bringing a charge of 3 nC from infinity to the third corner of the triangle is _ _ _ _ J . 1 4 ₀ =9 10⁹ ~N . m ² / C ²

Step-by-step solution

Two point charges of 1 nC and 2 nC are placed at two corners of an equilateral triangle with side 3 cm. The work done in bringing a 3 nC charge from infinity to the third corner equals the charge times the potential at that point. Both source charges are at distance 0.03 m from the third corner. The potential due to the 1 nC charge is V₁ = 9 10^9 1 10⁻⁹ 0.03 = 300 V and due to the 2 nC charge is V₂ = 9 10^9 2 10⁻⁹ 0.03 = 600 V. Total potential: V_ total = 300 + 600 = 900 V Work done: W = 3 10⁻⁹ 900 = 2.7 10⁻⁶ J = 2