What is called the efficiency of a heat engine?

The efficiency of a heat engine is a value equal to the ratio of the perfect useful work of the engine to the energy received from the heater
Efficiency = Ap / Q1 or Efficiency (Q1 – Q2) / Q1 * 100%

where Ap is useful work, Q1 is the amount of heat received from the heater, Q2 is the amount of heat given to the refrigerator, (Q1 – Q2) is the amount of heat that was used to perform the work.

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.