Choose True or False by ticking (%u221A) the right answer. Each question carries
ID: 1858933 • Letter: C
Question
Choose True or False by ticking (%u221A) the right answer. Each question carries one mark.
1. 1-The change of entropy, when heat is removed from the gas, is positive T( ), F ( )
2. 2-The entropy of steam will increase, as it flows through an actual adiabatic turbine. T( ), F ( )
3. 3- The single-stage compression process of an ideal Brayton cycle without regeneration is replaced by a multistage compression process with intercooling between the same pressure limits. As a result of this modification, the compressor work decreases. T( ), F ( )
4. 4- The compression ratio for reciprocating engines is the ratio of the maximum to minimum pressures in the cylinder. T( ), F ( )
5. 5- In open feedwater heaters, the two fluids actually mix, but in closed feedwater heaters there is no mixing. T( ), F ( )
6. 6- In combined gas-steam cycles, the energy source for the steam is the waste energy of the exhausted combustion gases. T( ), F ( )
7. 7-The coefficient of performance (C.O.P) is the reciprocal of the efficiency. T( ), F ( )
8. 8- The condition of refrigerant after leaving the compressor and before entering the condenser is superheated vapor. T( ), F ( )
9. 9-Liquid fuels have higher calorific value than solid fuels. T( ), F ( )
10. 10-The amount of heat given out by the complete combustion of 1 kg of fuel is known as calorific value of solid or liquid fuel. T( ), F ( )
11. 11-A point, in a compressible flow where the velocity is of fluid zero is called critical point T( ), F ( )
12. 12-The ratio of velocity of fluid in undisturbed stream to the velocity of sound wave is known as Mach number T( ), F ( )
Explanation / Answer
1. F as entropy increases with temperature.
2. F , no heat exchange takes place , hence entropy is constant
3. T
4 . F
5. F
6 . T
7.F
8.F
9. T
10.T
11.T
12.F