Problem 1 True of False 1 Flow work is the energy needed to

Problem 1 True of False ?
1. Flow work is the energy needed to push a fluid into or out of a control
volume, and it is equal to P.
2. For steady-flow process, the mass and energy contents of a control volume
remain constant.
3. The units m2/s2 and J/kg are equivalent.
4. Throttling valves are devises that keep pressures constant between the inlet
and the exit streams.
5. The temperature of an ideal gas does not change during a throttling process.

7. Both steady - flow and unsteady - flow systems can involve boundary work.
8. A diffuser is a device that decreases the kinetic energy of the fluid.
9. For adiabatic mixing chambers, the total energy leaving along with exit
streams is equal to the total energy entered along with the inlet stream(s).
10. During irreversible heat transfer process (say, 1 2), the amount of heat
transferred can be obtained from:

11. One method to increase the thermal efficiency of Carnot heat engine is to
(select one answer):
a) Reduce TH.
b) Reduce TL.
c) Increase TL.
d) Let TH and TL become equal.
12. There are two devices in the Rankin Cycle in which pressure drop is
negligible (select one answer):
a. Pump and Boiler
b. Condenser and Turbine
c. Turbine and Pump
d. Boiler and Condenser

Solution

1. False --- Definition is correct but flow work is equal to PV

2. True

3. True

4. False --- In throttling devices Enthalpy constant, but pressure decreased.

5. True

7. True

8. True

9. True

11. (B) Reduce TL

12. (D) Boiler and condenser