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 .The thermal efficiency of this engine is closest to

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