Topic: Electronics Engineering
Which of the following is the correct continuity equation:
- A. $\nabla\cdot J=\frac{\partial p}{\partial t}$
- B. $\nabla\cdot J=-\frac{\partial\rho}{\partial t}$
- C. $\nabla\cdot J=0$
- D. $\nabla\cdot J=\frac{\partial E}{\partial t}$
Answer: B. $\nabla\cdot J=-\frac{\partial\rho}{\partial t}$
Explanation: Continuity equation is $\nabla\cdot J=\frac{-\partial\rho}{\partial t}$