Question

At the center of a square of side 2 cm a charge of 2 is placed. What is the work done in moving
a charge of 1 C from a corner to the opposite corner ?
(A) 0.04 J (B) 0 J (C) 0.4 J (D) 0.2 J

Answer 1

▶ Solution :

Given :

A charge of 2C is placed at the centre of the square of side 2cm.

To Find :

Work done in moving a charge of 1C from a corner to the opposite corner.

Formula :

Formula of electrical potential energy in terms of charge and distance is given by

$\boxed{\bf{\pink{U=\dfrac{kq_1q_2}{r}}}}$

Concept :

▪ This question is completely based on concept of work-energy theorem.

▪ As per WET, work done is always equals to the change in potential energy.

Calculation :

$\implies\bf\:W=\Delta(PE)\\ \\ \implies\sf\:W=(PE)_f-(PE)_i\\ \\ \implies\sf\:W=\dfrac{k(2)(1)}{\sqrt{2}}-\dfrac{k(2)(1)}{\sqrt{2}}\\ \\ \implies\boxed{\bf{\purple{W=0\:J}}}$