A charge of 20μC produces an electric field. Two points are 10 cm and 5 cm away from this charge. Find the values of potentials at these points and also find the amount of work done to take an electron from one point to the other.
VA=14πϵ0qrA=9×109×20×10−60.05
VA=36×10−5V
VB=14πϵ0qrB=9×109×20×10−60.1
VB=18×10−5V
Work done=e△V
W=1.6×10−19(36×10−5−18×10−5)
W=28.8×10−24j=0.18meV