A steam turbine is employed to turn a generator. The input power to the turbine is $P_I$ and the output power is $P_O$. The power loss in the turbine is $P_L$, as illustrated. What is the efficiency of the turbine?
- A$\frac{P_L}{P_O}$
- B$\frac{P_I}{P_O}$
- C$\frac{P_L}{P_I}$
- D$\frac{P_O}{P_I}$