WorksheetsEnergy Conversion Quiz 1 Review
Total questions: 12
Worksheet time: 14mins
What do you call a person who works with thermodynamics?
Thermodynamician
Thermodynamist
Thermodynamicist
Thermodynamic
What does the variable "h" mean in this course?
Specific Empathy
Convection Coefficient
Computational Mesh Size
Specific Enthalpy
Specific Energy
Why is enthalpy constant for flow through a throttle valve? (h1 = h2)
Enthalpy is not actually constant
Throttling is a reversible process
No work or heat is exchanged
"Throttle" is spelled with an "h", so h is constant
What is the work input to this internally irreversible heat pump?
800 W
200 J
5/3
200 W
What temperature should be used for all work loss calculations in this house heating system?
TL = 265 K
T0 = 275 K
Thouse = 293 K
TH = 300 K
Which statement is true regarding compression and expansion processes in open systems?
No heat exchange in all compression/expansion processes (Tds = 0)
Irreversible processes aren’t realistic
No entropy generation in all compression/expansion processes
Work output should be positive during compression
Air (ideal gas with VARIABLE specific heats) at state 1 (T1 = 280 K, p = 100 kPa) is isentropically compressed to state 2 with a compression ratio of 12. What is the best way to find T2?
Not enough information to get T2
T2 = 280 K
Use:
vr(T1)/vr(T2) = 12
Use:
pv = RT,
v1/v2 = 12,
and
Tv(k-1) = const
Air (ideal gas with CONSTANT specific heats) at state 1 (T1 = 280 K, p = 100 kPa) is isentropically compressed to state 2 with a pressure ratio of 3. What is the best way to find T2?
Not enough information to get T2
T2 = 280 K
Use:
pr(T2)/pr(T1) = 3
Use
p2/p1 = 3
and
Tp(k-1)/k = const
Steam at 500 °C and 5 MPa (s1 = 6.98 kJ/kgK) expands through a reversible turbine, exiting at 500 kPa. What is the state of the fluid after expansion?
Saturated Liquid
2-Phase Liquid/Vapour mix
Saturated Vapour
Superheated Vapour
Compressed liquid water at 20 °C, 1 MPa flows through a heater. At the outlet, its temperature is Tsat(1 MPa). What is its state at the outlet?
Saturated Liquid
Saturated Vapour
2-phase Liquid/Vapour Mix
Any of the above
None of the above
An irreversible closed system exchanges work and heat with its surroundings from state 1 → 2. What can we say about S1 and S2?
Not enough information to compare S1 and S2
S1 is greater than S2
S2 is greater than S1
S1 = S2
An irreversible closed system exchanges work and heat with its surroundings from state 1 → 2. What can we say about Sgen,1→2?
Not enough information to find Sgen
Sgen is greater than 0
Sgen is less than 0
Sgen is 0
