Three particles, each having a charge of 10 micro coulomb are placed at the vertices of an equilateral triangle of side 10cm. Find the work done by a person in pulling them apart to infinite separations .
Three point charges 1C,2C and−2C are placed at the vertices of an equilateral triangle of side 1 metre. The work done in joules by an external force to increase the separation of the charges to 2 metres is :