Consider a cycle followed by an engine, (figure)

1 to 2 is isothermal 2 to 3 is adiabatic 3 to 1 is adiabatic
such a process does not exist because

Options

A. heat is completely converted to mechanical energy in such a process which is not possible
B. mechanical energy is completely converted to hjeat in this proces , which is not possible
C. curves representign two adiabatic process can intersect
D. curves representing an adiabatic process and an isothermal process don't intersect

Answer

A

Explanation

In one complete cycle, `1rarr2rarr3rarr3rarr1`, the systeme returns to its initial state so dU = 0 and dQ =dW i.e het is completyely cnverted in to mechanical energy in the given prpocess .It is not possible further two adiabatic curve `2rarr3and 3rarr1` connot intesect each other.