question_answer

  Which of the following equations are forms of continuity equations?                     

(\[\overrightarrow{V}\]is the velocity and \[\forall \] is volume)

1. \[{{A}_{1}}{{\overrightarrow{V}}_{1}}={{A}_{2}}\overrightarrow{{{V}_{2}}}\]

2. \[1\frac{du}{\partial x}+\frac{dv}{\partial y}=0\]

3. \[\int\limits_{S}{\rho \overrightarrow{V}\,.\,dA+\int\limits_{\forall }{\rho \,d\forall =0}}\]

4. \[\frac{1}{r}\,\,\frac{\partial \,\left( r{{v}_{r}} \right)}{\partial r}+\frac{\partial {{v}_{z}}}{\partial z}=0\]

Select the correct answer using the codes below:

Codes:

A) 1, 2, 3 and 4                 

B) 1 and 2

C) 3 and 4            

D) 2, 3 and 4