Question

Is time rate of change of circulation around a closed curve is zero?

(a) True

(b) False

The question was posed to me by my school principal while I was bunking the class.

Question is taken from Kelvin’s Circulation Theorem and the Starting Vortex in chapter Incompressible Flow over Airfoils of Aerodynamics

Answer 1

Correct answer is (a) True

The best I can explain: The time rate of change of circulation around a closed curve consisting of the same fluid elements is zero, change in circulation with respect to time is zero, along which its supporting discussion is called kelvin’s circulation theorem.