The maximum hydraulic efficiency of an impulse turbine is (where ≈ì√ú = Angle of blade tip at outlet)$

The maximum hydraulic efficiency of an impulse turbine is (where ≈ì

1.	The maximum hydraulic efficiency of an impulse turbine is (where ≈ì√ú = Angle of blade tip at outlet)$
A.	(1 + cos ≈ì√ú)/2
B.	(1 - cos ≈ì√ú)/2
C.	(1 + sin ≈ì√ú)/2
D.	(1 - sin ≈ì√ú)/2
Answer» B. (1 - cos ≈ì√ú)/2