Gauss's Law: Practice Problem & Solution
Three point charges $+q$, $-2q$ and $+q$ are placed at points $(x=0, y=a, z=0)$, $(x=0, y=0, z=0)$ and $(x=a, y=0, z=0)$ respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are: (2007)
Solution Explained:
To solve this problem, we apply the core principles of Gauss's Law. Understanding the underlying formula is key to arriving at the correct answer below:
The system can be considered as two dipoles, each of moment $p = qa$, along the x and y axes. The resultant dipole moment is $p_{net} = \sqrt{p^2 + p^2} = \sqrt{2}qa$. Its direction is along the line joining $(0,0,0)$ to $(a,a,0)$.
Leave a Reply