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WorksheetsEnergy Conversion Quiz 1 Review
Total questions: 11
Worksheet time: 11mins
What do you call a person who works with thermodynamics?
Thermodynamician
Thermodynamist
Thermodynamicist
Thermodynamic
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 to 500 kPa. What is the state 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
