Question

Compression stroke results in ________

(a) Formation of negative loop

(b) Formation of positive loop

(c) Formation of an infinite loop

(d) Formation of no loop

I have been asked this question during an interview.

Enquiry is from Turning Moment Diagram for a Four Stroke Cycle Internal Combustion Engine in division Turning Moment Diagrams and Flywheel of Machine Dynamics

Answer 1

Correct choice is (a) Formation of negative loop

To explain I would say: During compression stroke, the work is done on the gases, the pressure inside the cylinder decreases and has a value lower than the atmospheric pressure, as a result a negative loop is formed.