Question

Aerofils are so designed that the speed of air:

• A. on top side is more than on lower side
• B. on lop side is less than on lower side
• C. is same on both sides
• D. is turbulent

Answer 1

Answer: (A)

on top side is more than on lower side

Answer 2

The aerofils are so designed that $P_{\text {upper side }}< P_{\text {lower side }}$ so that the aerofils get a lifting force in upward direction. According to Bernoulli's theorem, where the pressure is large, the velocity will be minimum or vice-versa. Thus, $v_{\text {upper side }} > v_{\text {lower side }}$