question_answer

  Which one of the following is the continuity equation in differential form?                             (The symbols have usual meanings)

A) \[\frac{dA}{A}+\frac{dV}{V}+\frac{d\rho }{\rho }=\text{constant}\]

B) \[\frac{dA}{A}+\frac{dV}{V}+\frac{d\rho }{\rho }=0\]

C) \[\frac{A}{dA}+\frac{V}{dV}+\frac{\rho }{d\rho }=\text{constant}\]

D) \[AdA+VdA+\rho d\rho =0\]