Question
GeneralGeneralGeneral

Two point charges 1 nC and 3 nC are placed at two corners of an equilateral triangle of side 3 cm. Find the work done in bringing a charge of 3 nC from infinity to the third corner of the triangle.

Verified Answer

Solution:

Given:

  • q1 = 1 nC = 1 × 10-9 C
  • q2 = 3 nC = 3 × 10-9 C
  • q0 = 3 nC = 3 × 10-9 C
  • Side of triangle = 3 cm = 0.03 m

Potential at the third vertex due to the two charges:

V = kq1/r + kq2/r

= (9 × 109) [(1 × 10-9 + 3 × 10-9)/0.03]

= (9 × 109) (4 × 10-9) /0.03

= 36/0.03

= 1200 V

Work done in bringing charge q0:

W = q0V

= (3 × 10-9)(1200)

= 3.6 × 10-6 J

Answer:

3.6 × 10-6 J