Question

Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle ____________

(a) combustion is at constant volume

(b) expansion and compression are isentropic

(c) maximum temperature is higher

(d) heat rejection is lower

I had been asked this question by my college professor while I was bunking the class.

My question is based upon Comparison of Otto, Diesel and Dual Cycle topic in chapter Air Standard Cycles and their Analysis of IC Engine

Answer 1

Right answer is (d) heat rejection is lower

The explanation is: None.