Question

When the work is done 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 international level competition.

Asked question is from Turning Moment Diagram for a Four Stroke Cycle Internal Combustion Engine topic in chapter Turning Moment Diagrams and Flywheel of Machine Dynamics

Answer 1

Correct answer is (a) Formation of negative loop

To explain: When 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.