THRM 6006 - Introduction to Thermodynamics (Chp 8) Flashcards
Using Steam Table 1 in ‘Academic Supplement’ determine which of the following is the saturation temperature at 600 kPa?
A) 158.85°C B) 158.0°C C) 160.58°C D) 158.5°C E) 701.3°C
A) 158.85°C
Radiation from the furnace fire:
A) Travels in straight lines
B) Is present in oil firing but not fuel gas firing
C) Radiates through the superheater tubewalls
D) Radiates through the water in the waterwalls
E) Requires a transfer medium
A) Travels in straight lines
The transfer of heat involving the movement of a fluid is defined as:
A) Conduction B) Superheating C) Refrigeration D) Radiation E) Convection
E) Convection
The coefficient of expansion of metals (use table page 28 of Academic Supplement”) :
A) Is greater for steel than for copper
B) Is greater for copper than for steel
C) Is a constant for all non-ferrous metals
D) Is less for linear expansion than for volumetric expansion
E) Has the units “mm per m”
B) Is greater for copper than for steel
Which of the following statements about heat is true?
A) Specific heat is the same for every substance
B) Specific heat capacity is the same for every state of matter of the same substance
C) 1 J is less than 1 Nm of work
D) If there is a temperature difference between the heat source and a cooler object in contact with the source, heat will be transferred to the cooler object
E) Heat can be transferred from cold bodies to hot bodies without using an external supply of work
D) If there is a temperature difference between the heat source and a cooler object in contact with the source, heat will be transferred to the cooler object
If a 1 kg sample of steam has 0.2 kg of water droplets in it, then it would have:
A) Enthalpy of 98 kJ B) None of the above C) A dryness fraction of 80% or 0.8 D) An entropy of 98 kJ/K E) A wetness fraction of 80%
C) A dryness fraction of 80% or 0.8
The unit used for specific volume in the Steam Tables (in the “Academic Supplement”) is:
A) m³/kg B) cm³/kg C) mm³/g D) cm³/g E) m³/g
D) cm³/g
How much energy is required to raise 63 kg of ice at 0ºC to saturated steam at 100ºC? Specific heat capacity of water 4.2 kJ/kg/’C. Specific latent heat of ice 335 kJ/kg/’C. Specific latent heat of steam 2257 kJ/kg/’C.
A) 35 490 kJ B) 189 756 kJ C) 53 107 kJ D) 273 097 kJ E) 21 775 kJ
B) 189 756 kJ
_________ heat is heat that causes a change of state of a substance without changing its temperature.
A) Latent B) Specific C) Super D) Saturated E) Sensible
A) Latent
Calculate the amount of expansion occurring when a steel pipe 150 m long is heated from 80 to 280°C.
A) 0.45 m B) 0.65 m C) 0.50 m D) 0.75 m E) 0.36 m
E) 0.36 m
Convert -35° Celsius to Fahrenheit, if °F = 9/5 °C + 32.
A) -20 B) -35 C) -1.8 D) -10 E) -31
E) -31
A steam pipe 450 m long is installed at an ambient temperature of 20°C. When in service, the pipe will carry steam at 520°C.
If the coefficient of linear expansion of steel is 12x10¯6 / °C, how much will the line increase in length when put into service?
A) 2.7m B) 1.008m C) 0.9m D) 3.25m E) 2.91m
A) 2.7m
The flow of heat from molecule to molecule within a substance or from molecules of one body to those of another body in direct contact with it is defined as: A) Latent heat of fusion B) Conduction C) Specific heat D) Absolute temperature E) Convection
B) Conduction
Columns 8, 9 and 10 of Table 1 of the Steam Tables in “Academic Supplement” deal with which type of energy?
A) Enthalpy B) Entropy C) Specific energy D) Internal energy E) Potential energy
A) Enthalpy
The amount of heat to raise the temperature of a unit mass of a substance 1°C without changing the state of the substance is defined as:
A) Specific heat B) Absolute zero C) Radiation D) Latent heat E) Saturation temperature
A) Specific heat
