Helium in an Ideal Diesel Cycle Is Compressed from 4

Multiple Choice

Helium in an ideal Diesel cycle is compressed from 4 L to 0.25 L, and then it expands during the constant pressure heat addition process to 0.50 L. Under air standard conditions, the thermal efficiency of this cycle is

A) 20.5%
B) 84.3%
C) 79.5%
D) 61.4%
E) 67.4%