A Heat Engine Performs the Reversible Cycle Abca with 9

Multiple Choice

A heat engine performs the reversible cycle abca with 9.0 moles of an ideal gas, as shown in the figure. Path ca is an adiabatic process. The temperatures at points a and b are 300 K and 500 K, respectively. The volume at point c is 0.20 m³. The adiabatic constant of the gas is 1.60. The thermal efficiency of this engine is closest to

A) 0.070.
B) 0.10.
C) 0.13.
D) 0.16.
E) 0.19.