The efficiency of an impulse turbine is maximum when (where Vb = Blade speed, V = Absolute velocity of steam entering the blade, and α = Nozzle angle)

The efficiency of an impulse turbine is maximum when (where Vb = Blade

1.	The efficiency of an impulse turbine is maximum when (where Vb = Blade speed, V = Absolute velocity of steam entering the blade, and α = Nozzle angle)
A.	Vb = 0.5 V cos α
B.	Vb = V cos α
C.	Vb = 0.5 V2 cos α
D.	Vb = V2 cosα
Answer» B. Vb = V cos α