Question

In which process in a Carnot's heat engine, heat $\left(Q_1\right)$ is absorbed from a heat source?

• A. Reversible isothermal expansion
• B. Reversible isothermal compression
• C. Reversible adiabatic expansion
• D. Reversible adiabatic compression

Answer 1

The correct option is A Reversible isothermal expansion

Carnot's heat engine will follow carnot cycle.
In a Carnot's cycle the first step is a reversible isothermal expansion during which the working substance in the system absorbs heat from a heat source (which is at a higher temperature) and expands by doing work on surroundings.