Question

Consider a cycle followed by an engine as shown in figure
1 to 2 is isothermal
2 to 3 is adiabatic
3 to 1 is adiabatic
Such a process does not exist because

• A. heat is completely converted to mechanical energy in such a process, which is not possible.
• B. mechanical energy is completely converted to heat in this process, which is not possible.
• C. curves representing two adiabatic processes can intersect.
• D. Curves representing an adiabatic process and an isothermal process dont intersect.

Answer 1

The correct option is A heat is completely converted to mechanical energy in such a process, which is not possible.

Heat change is converted to mechanical energy. Since efficiency of no machine is $100\%$ it is not possible.