Question

A system has two charges $qA=2.5\times {10}^{-7}C$ and $qB=-2.5\times {10}^{-7}C$ located at point $A(0,0,-15)cm$ and $B(0,0,15)cm$ respectively. What are the total charge and electric dipole moment vector of the system?

Answer 1

At A, amount of charge, $q_A$= $2.5\times {10}^{-7}C$ (Given)

At B, amount of charge, $q_B=-2.5\times {10}^{-7}$

Total charge of the system,

$q=q_A+q_B=2.5\times {10}^{-7}C=0$

Distance between two charges at points A and B,

$d=15+15=30cm=0.3m$

Electric dipole moment of the system is given by,

$p=q_A\times d=2.5\times {10}^{-7}\times 0.3=7.5\times {10}^{-8}cm$ along positive z-axis.

Therefore, the electric dipole moment of the system is$7.5\times {10}^{-8}$ along the positive z-axis.