# Q.The maximum hydraulic efficiency of an impulse turbine is (where φ = Angle of blade tip at outlet)

• A(1 + cos φ)/2
• B(1 - cos φ)/2
• C(1 + sin φ)/2
• D(1 - sin φ)/2

(1 + cos φ)/2

Hints :

According to Bernoulli's equation for steady ideal fluid flow

A Francis turbine is used when the available head of water is