What is the nature of the flow having a velocity potential?

A)
Viscous
B)
Inviscid
C)
Rotational
D)
Irrotational

Correct Answer :   Irrotational


Explanation : For irrotational flow, curl of velocity vector yields zero. In case the curl of any vector is zero i.e.∇ × V = 0, where V is a vector, it is also expressed in the form of ∇ζ where ζ is a scalar function. In case of irrotational flow, velocity potential ? is the scalar function. Hence if the flow has a velocity potential, it automatically implies that it is irrotational.