1. What is the principle on which Steam power plant is based?
2. What is Rankine cycle ? Explain it completely.
3. What is sensible heating, latent heating & superheating?
4. What is the efficiency of modern power plant?
5. How can we increase the efficiency of plant?
6. Show any one process to increase the efficiency on T-s diagram.
7. Why the efficiency is low(35-40 %) for steam power plant ?
8. What are the various losses in power plant? Explain all briefly.
9. How to reduce the losses in boiler?
10. What is air preheater?
11. What is X-factor for an air preheater ? ( I positively replied , ’sorry sir ’I do not recall X- factor at this time. The interviewer just gave a smile and said ”its ok ,no problem”)
12. What is supercritical boiler?
13. Draw a T-s diagram showing supercritical boiling?
14. What are the main advantages of using supercritical boilers in place of traditional boilers?
15. What is the main difference in Mild Steel and Cast Iron?( I told the difference on the basis of carbon percentage in MS and CI but he asked me to elaborate the same. So I replied the difference again on the basis of properties, applications. He asked me to give support examples for applications of CI and MS.
16. What is compressor?
17. If you are having two compressors,in first one you are increasing pressure from 1 bar to 15 bar and in 2nd one from 15 bar to 200 bar. Which one will consume more work and why?

18.What is ductility?
19.What is malleability?
20.What is the main difference in ductility and malleability? (I replied it on the basis of type of force that we use on workpiece during operation i.e. tensile force for ductility and compressive force for malleability.)

1. What is the meaning of your name?
2. From where do you belong to?(they asked me 4-5 questions regarding my hometown)
3. About my family background….

Just be confident during interview.They can ask any subject so prepare basics well.
at last

Have faith in God and in Yourself !

Best of Luck !!!!!!

Shortlisting was on the basis of CPI.Total 9 from mechanical were shortlisted and finally 3 were given offer in NTPC (including me).
It was the CPI and confidence and a sound knowledge of subjects that went in my favour.