You have access to two sources of energy that can be used to turn a steam turbine in a heat engine (a steam turbine is a device that converts thermal energy into mechanical work):
1. Superheated steam at 400°C and 20 bar
2. Superheated steam at 600°C and 20 bar
Which of these two energy sources can be converted into more mechanical work per unit mass of flowing steam in a heat engine? You may assume that each steam source will leave the turbine at 200°C and 1 bar.

Option 2.

Explanation:

A turbine produces mechanical work at the expense of fluid energy, that is to say according to the First Law of the Thermodynamics:

The conditions at inlet and outlet are, respectively:

Inlet - Option 1 (Superheated Steam)

Inlet - Option 2 (Superheated Steam)

Outlet (Superheated Steam)

The mechanical work per unit mass of each option is determined hereafter:

The second option offers more mechanical work per unit mass.

answer:

the answer is d

explanation: