question_answer

Maximum blade efficiency of a Parson's turbine is given by:       (\[\alpha \] is nozzle angle) 

A) \[\frac{{{\cos }^{2}}\alpha }{1+2{{\cos }^{2}}\alpha }\]                    

B) \[\frac{\cos \alpha }{1+2{{\cos }^{2}}\alpha }\]

C) \[\frac{2{{\sin }^{2}}\alpha }{1+2{{\sin }^{2}}\alpha }\]                    

D) \[\frac{2{{\cos }^{2}}\alpha }{1+2{{\cos }^{2}}\alpha }\]