Question

A circular cylinder held in uniform flow from north to south as shown in the figure, is rotated about its own axis in an anticlockwise direction. It will experience a lift force in the direction of

• A. N
• B. S
• C. E
• D. W

Answer 1

The correct option is D W

As cylinder is rotated anticlockwise and wind is coming from north direction. Resultant velocity on the left half portion will be $V+\omega R$ and on right half portion will be $V-\omega R$. Thus pressure on left half will be less and on right half will be more and lift will be in the west direction