What is the term used for a case where source and sink( both of them are of equal magnitude) approach each other such, distance between them reduces and product of distance and discharge magnitude remains constant.

What is the term used for a case where source and sink( both of them a

1.	What is the term used for a case where source and sink( both of them are of equal magnitude) approach each other such, distance between them reduces and product of distance and discharge magnitude remains constant.
A.	A plain pair
B.	A doublet source in uniform
C.	Hagen Poiseuille flow
D.	Coutte flow
Answer» C. Hagen Poiseuille flow