Three charges, each +q, are placed at the corners of an isosceles triangle ABC of sides BC and AC, 2a. D and E are the mid points of BC and CA.
The work done in taking a charge Q from D to E is
Zero
Given:
AC=BC and D & E are midpoints of BC and AC respectively.
?DC=DB=EC=EA
Also, using geometry it can be proved that BE=DA
As all charges at A, B and C are equal and distances of D and E from A, B and C are also equal, it can be concluded from symmetry that the potentials at D and E are equal.
The work done in taking a charge Q from D to E is independent of the path taken and is given by