Question

2 like charges of magnitude 10e-9 coulomb are separated by a distance of 2 m in true space. if distance is increased to 4m then the ratio of their electric potential energies is

Answer 1

Since electric potential energies=work done
w=kqq/r ;w is inversely proportional to r
w1/w2=2/6 w2=3w1 or w1:w2=1:3
hope you would understand