Power Plant Questions and Answers – Thermodynamics of Brayton-Rankine Combined Plant – I

This set of Power Plant Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Thermodynamics of Brayton-Rankine Combined Plant – I”.

1. If p and q are the efficiencies of a Brayton & Rankine cycles respectively in a Brayton-Rankine combined plant, the efficiency n of a combined plant is?
a) n = p/q
b) n = p+q-pq
c) n = pq
d) n = (1 – pq)
View Answer

Answer: b
Explanation: The efficiency of a Brayton-Rankine combined plant when p and q are the efficiencies of a Brayton & Rankine cycles respectively is given as,
n = p + q – pq.

2. Which of these is a working fluid in the topping plant of a Brayton-Rankine combined plant?
a) Hydrogen
b) Helium
c) Nitrogen
d) All of the mentioned
View Answer

Answer: b
Explanation: The low molecular mass of Helium makes it the most suitable working fluid in the topping plant.

3. Which of these is a working fluid in the bottoming plant of a Brayton-Rankine combined plant?
a) Mercury
b) Steam
c) Water
d) Air
View Answer

Answer: c
Explanation: Water is the bottoming fluid due to its high specific heat capacity.
advertisement
advertisement

4. What would be the temperature of the gas in the combustion chamber?
a) 500 °C
b) 1600 °C
c) 1200 °C
d) 650 °C
View Answer

Answer: b
Explanation: The gas in the combustion chamber is at a temperature of 1600 °C.

5. The efficiency of the open cycle gas plant is quite low. Why?
a) Gas gets cooled before reaching the turbine wheels
b) A lot of mechanical energy is used up by the compressor
c) Due to the presence of regenerator and absence of air pre heater
d) Both Gas gets cooled before reaching the turbine wheels and a lot of mechanical energy is used up by the compressor
View Answer

Answer: d
Explanation: The efficiency of the open cycle gas plant is quite low. This is because of mainly two reasons,
Gas gets cooled before reaching the turbine wheels and a lot of mechanical energy is used up by the turbine wheels.
Note: Join free Sanfoundry classes at Telegram or Youtube

6. To improve the efficiency of the gas turbines, which among these are used?
a) Regenerator
b) Inter cooling
c) Reheating
d) All of the mentioned
View Answer

Answer: d
Explanation: All of the methods- Reheating, Regeneration and Intercooling are used to improve the efficiency of gas turbines.

7. What is regeneration?
a) Removal of heat from compressed air between stages of compression
b) Transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber
c) To increase the temperature of partially expanded gases by burning more fuel
d) Transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber and increases the temperature of partially expanded gases by burning more fuel
View Answer

Answer: b
Explanation: Transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber is called the process of Regeneration.
advertisement

8. What is meant by inter cooling?
a) Removal of heat from compressed air between stages of compression
b) Transfer of heat energy from exhaust gases to the compressed air flowing between compressor and the combustion chamber
c) To increase the temperature of partially expanded gases by burning more fuel
d) None of the mentioned
View Answer

Answer: a
Explanation: Removal of heat from compressed air between various stages of compression is called Inter cooling.

9. Which material is used for the manufacture of the turbine blades?
a) Stainless steel
b) Carbon steel
c) High nickel alloy
d) High alloy steel
View Answer

Answer: c
Explanation: High nickel alloy is the most sufficient material for the manufacture of Turbine Blades.
advertisement

Sanfoundry Global Education & Learning Series – Power Plant Engineering.

To practice all areas of Power Plant Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.