Question

When the work is by on the gases, which of the following effect is observed on the turning moment diagram?

(a) Formation of negative loop

(b) Formation of positive loop

(c) Formation of an infinite loop

(d) Formation of no loop

I had been asked this question in an interview for job.

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

Answer 1

Correct choice is (b) Formation of positive loop

To explain I would say: When the work is done by the gases, the pressure inside the cylinder increases and has a value higher than the atmospheric pressure, as a result a positive loop is formed.