question_answer

Which one of the following equations gives the velocity distribution across a circular pipe having a viscous flow?

A) \[u={{u}_{\max }}\,[1-{{(r/R)}^{2}}]\]

B) \[u={{u}_{\max }}\,[{{R}^{2}}-{{r}^{2}}]\]

C) \[u={{u}_{\max }}\,{{[1-(r/R)]}^{2}}\]

D) \[u={{u}_{\max }}\,{{[1+(r/R)]}^{2}}\]