MCQs ​Mechanical Engineering

Q1. The efficieney of an ideal Carnot engine depends on

1. working substance
2. the temperature of the source only

Q2. Cornot cycle is not considered as a practical cycle because

1. its P-V diagram is narrow
2. its thermal efficiency is low

Q3. The efficiency of a carnot engine depends on

1. working substance
2. design of engine

Q4. Thermal plant works on :

1. Carnot cycle
2. Joule cycle

Q5. T₁ is high and T₂ is low temperature of a Carnot heat engine . Which is the most efficient way to increase efficiency ?

1. To increase T₁
2. To decrease T₂

Q6. Area under the curve of a T-S diagram represents –

1. Heat transfer for a reversible process
2. Heat transfer for an irreversible process

Q7. An engine operates between temperature limits 900 K and T₂ and another between T₂ and 400 K. For both engines to be equally efficient T₂ should be

1. 600 K
2. 700 K

Q8. A heat engine develops 60kW work having an efficiency of 60%, Amount of heat rejected will be

1. 400 kW
2. 10kW

Q9. In Carnot cycle addition and rejection of heat takes place at

1. Constant pressure
2. Constant temperature

Q10. A heat engine receives 1120 kJ of heat and rejects 840 kJ of heat while operating between two temperature limits of 560K and 280 K. It indicates that the engine operates on the following cycle

1. Reversible cycle
2. Irreversible cycl