If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the percentage increase in efficiency will be
A. 2%
B. 4%
C. 8%
D. 14%
Answer: Option D
Solution (By Examveda Team)
If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the percentage increase in efficiency will be 14%This Question Belongs to Mechanical Engineering >> Internal Combustion Engines (I.C. Engines)
%INCREASE ={(Final value-Initial value)/Initial value}*100
%efficiency increase={(.540 - .474) / .474}=13.92%
Efficiency for compression ratio 5 is 48%
Efficiency for C.r 7 is 54%
So increase in %age of efficiency is 6%
How it’s 14%?
When compression ratio is 5 then efficiency will be 47.4% and when it is 7, efficiency will be 54%
Hence increase in efficiency is 6.6%