Question

Which of the following does not hold for the zero-lift angle of attack?

(a) It is a negative value

(b) Denoted by αL=0

(c) It is zero for a symmetric airfoil

(d) Does not depend on the slope of the camber line

I have been asked this question by my school principal while I was bunking the class.

Asked question is from The Cambered Airfoil topic in portion Incompressible Flow over Airfoils of Aerodynamics

Answer 1

Right option is (d) Does not depend on the slope of the camber line

For explanation I would say: The zero lift angle of attack is the value of angle of attack where the lift is zero. It is a negative quantity and depends on the shape of the airfoil (slope of the camber line). It is zero for a symmetric airfoil.