What is the general formula for efficiency in the Rankine cycle?

The Rankine cycle is a thermodynamic cycle used primarily for converting heat into work, commonly in power plants. To determine the efficiency of the Rankine cycle, we look at how effectively it converts heat into mechanical energy (work).

The formula for efficiency in this context is derived from the relation between the useful work produced by the cycle and the heat energy supplied to it. The correct expression indicates that efficiency is calculated by taking the work done by the system and dividing it by the total heat supplied to the system during the process.

This relationship is significant because it measures the performance of the Rankine cycle: the more work produced for a given amount of heat input, the higher the cycle's efficiency. Thus, this answer accurately reflects the fundamental principle of energy conversion within the cycle.

The other formulas do not correctly define the efficiency of the Rankine cycle in the context of how work and heat are interrelated within the thermodynamic process.