Two fan wheels are rotating at the same speed. One wheel has forward curved blades and the other has backward inclined blades. The velocity of the air leaving the forward curved blades is considerably higher, because
a. The centrifugal force of the forward curved blades is higher.
b. The linear velocity of the forward curved blades is higher.
c. The air resistance of the backward inclined blades is much lower.
d. The velocity of the air leaving the fan blades, added to the linear velocity of the fan blades, is greater with the forward-inclined fan blades than backward-inclined fan blades.
e. Fans with forward curved blades must be constructed with larger diameter wheels to provide the same airflow as a fan with backward-inclined blades.
Answer: D