What is the basis for analyzing an energy transfer diagram?

Question

The mechanical energy input and output must be equal.
Heat must always be the largest output.
The sum of all outputs must equal the input.
Electrical energy is an input but not an output.

Answer 1

The best basis for analyzing an energy transfer diagram from the options given is:

The sum of all outputs must equal the input.

This principle aligns with the law of conservation of energy, which states that energy cannot be created or destroyed, only converted from one form to another. In any system, the total energy input must equal the total energy output, accounting for all forms of energy involved (mechanical, thermal, electrical, etc.).