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 i $s ______$ μJ.
1/(4πε₀) = 9 × 10⁹ N·m²/C²

Question

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 i $s ______$ μJ.

1/(4πε₀) = 9 × 10⁹ N·m²/C²

G1 Physics · Accepted Answer

Potential at the third corner due to the first two charges is V = k(q₁+q₂)/l. Here, q₁ = 1 nC, q₂ = 2 nC, l = 3 cm = 0.03 m. Therefore, V = (9×10⁹) [(1+2)×10⁻⁹]/0.03 = 900 V. Work done in bringing q₃ = 3 nC from infinity is W = q₃V = 3×10⁻⁹×900 = 2.7×10⁻⁶ J = 2.7 μJ. Correct option: A.

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 i s ______ μJ. 1/(4πε₀) = 9 × 10⁹ N·m²/C²