Question

Identify the indicator diagram out of the following.
A.

B.

C.

D.

Answer 1

Hint: In order to answer this question, you should know what an indicator diagram actually is. There would definitely be some signature feature for these diagrams that defines them. Now cross check which among the given diagrams in the question correctly represents an indicator diagram.

Complete answer:
An indicator diagram is basically a chart and could be used to record the pressure in the cylinder versus the volume that is swept by a piston in compressors, etc. This diagram was developed by the Scottish inventor James watt and was used in understanding how the efficiency of steam engines could be improved.
In short, an indicator diagram is the plot of pressure against volume. Among the diagrams given in the question only one is a plot of pressure against volume and we could say that would be the indicator diagram among them.

Hence option C is the correct answer.

Additional information:
We have 4 types of indicator diagrams. They are:
(a) Power card
(b) Draw card
(c) Light spring diagram
(d) Compression diagram
Using the above mentioned indicator diagram, we could determine and also interpret a lot of things. Things like, the compression pressure and peak pressure inside a cylinder, the actual power that is generated, also the faulty combustion chamber parts and injection parts along with fuel timing and even exhausting and scavenging process are determined and interpreted.

Note:
We could normally compare the newly made indicator diagram with a reference diagram that indicates the ideal condition. If you observe any deviation from it, that would directly imply that there exists a fault. This fault could be any part of the engine. These deficiencies could also arise from incorrect adjustment of indicator instruments.