Helium gas in an ideal Otto cycle is compressed from 12

Question

Helium gas in an ideal Otto cycle is compressed from 12<°C and 2 L to 0.25 L, and its temperature increases by an additional 800°C during the heat addition process. The temperature of helium before the expansion process is
A)1668°C
B)1182°C
C)1941°C
D)812°C
E)575°C

Quizplus · Accepted Answer

Solved by EES Software. Solutions can be verified by copying-and-pasting the following lines on a blank EES screen. 
k=1.667
V1=2
V2=0.25
r=V1/V2
T1=12+273 "K"
T2=T1*r^(k-1)
T3=T2+800-273 "C"
"Some Wrong Solutions with Common Mistakes:"
W1_T3 =T22+800-273; T22=T1*r^(k1-1); k1=1.4 "Using wrong k value"
W2_T3 = T3+273 "Using K instead of C"
W3_T3 = T1+800-273 "Disregarding temp rise during compression"
W4_T3 = T222+800-273; T222=(T1-273)*r^(k-1) "Using C for T1 instead of K"

Helium Gas in an Ideal Otto Cycle Is Compressed from 12<°C