Power Engineering 3A1 – 3 & 4 Quiz Review Questions
With Complete Solutions
A copper vessel of water equivalent of 0.3 kg contains 7 kg of
water. The initial temperature of 21 degrees Celsius is increased
to 47 degrees Celsius. How much heat, in kJ, has been
transferred?
Using the common formula: Q = mc(t2-t1) and the relationship:
m = mwater+ mwater equivalent
A) 108.8
B) 793.9
C) 326.3
D) 761.3
E) 426.3
B
How much heat is taken from 29 kilograms of steam, initially at
100 degrees Celsius, that eventually becomes water at 6 degrees
Celsius. State your answer in MJ.
A) 86.9
B) 76.9
C) 66.9
D) 96.9
E) 106.9
B
The quantity of saturated water contained in a unit quantity of
steam is indicated by the
,A) moisture index.
B) partial pressure.
C) dryness fraction.
D) steam temperature.
E) saturation index.
C
1 kg of saturated steam at 200 kPa absolute has a dryness
fraction of 95%. Calculate the total heat content.
A) 2589.91 kJ
B) 2596.5 kJ
C) 2611.3 kJ
D) 2706.7 kJ
E) 2091.8 kJ
B
The principle of cathodic protection is to change the whole
surface of the metal into a cathode so that
A) the metal acts as an insulator to the flow of electrons.
B) the flow of electrons from the metal surface is equal across
the entire surface which reduces pitting and other corrosive
actions.
C) the electrolyte will not be able to support the flow of
electrons.
D) there is no net flow of current from any point of the metal
surface to the electrolyte.
E) the anode will move to a less critical part of the equipment.
, D
Sulphide stress corrosion cracking occurs in steel and other high
strength alloys when they are exposed to
A) salt water in concentrations high enough to produce an
electrolyte.
B) dry hydrogen sulphide environments.
C) moist hydrogen sulphide environments.
D) acidic environments.
E) sodium sulphite solution at pressures between 2 MPa and 6
MPa.
C
Stress corrosion cracking occurs rapidly in steels and certain
copper containing materials.
A) True
B) False
B
Biological corrosion is caused by (select all that apply)
1) bacteria boring into the metal surface and laying their eggs.
2) the generation of hydrogen sulphide caused by the bacteria.
3) bacteria eating the metal surface for food, as it multiplies
every 20 minutes.
4) increased oxygen generated by the bacteria at or near the
surface of the material.
5) the generation of gases that make the water more acidic, and
therefore more corrosive.
A) 2, 3, 4
With Complete Solutions
A copper vessel of water equivalent of 0.3 kg contains 7 kg of
water. The initial temperature of 21 degrees Celsius is increased
to 47 degrees Celsius. How much heat, in kJ, has been
transferred?
Using the common formula: Q = mc(t2-t1) and the relationship:
m = mwater+ mwater equivalent
A) 108.8
B) 793.9
C) 326.3
D) 761.3
E) 426.3
B
How much heat is taken from 29 kilograms of steam, initially at
100 degrees Celsius, that eventually becomes water at 6 degrees
Celsius. State your answer in MJ.
A) 86.9
B) 76.9
C) 66.9
D) 96.9
E) 106.9
B
The quantity of saturated water contained in a unit quantity of
steam is indicated by the
,A) moisture index.
B) partial pressure.
C) dryness fraction.
D) steam temperature.
E) saturation index.
C
1 kg of saturated steam at 200 kPa absolute has a dryness
fraction of 95%. Calculate the total heat content.
A) 2589.91 kJ
B) 2596.5 kJ
C) 2611.3 kJ
D) 2706.7 kJ
E) 2091.8 kJ
B
The principle of cathodic protection is to change the whole
surface of the metal into a cathode so that
A) the metal acts as an insulator to the flow of electrons.
B) the flow of electrons from the metal surface is equal across
the entire surface which reduces pitting and other corrosive
actions.
C) the electrolyte will not be able to support the flow of
electrons.
D) there is no net flow of current from any point of the metal
surface to the electrolyte.
E) the anode will move to a less critical part of the equipment.
, D
Sulphide stress corrosion cracking occurs in steel and other high
strength alloys when they are exposed to
A) salt water in concentrations high enough to produce an
electrolyte.
B) dry hydrogen sulphide environments.
C) moist hydrogen sulphide environments.
D) acidic environments.
E) sodium sulphite solution at pressures between 2 MPa and 6
MPa.
C
Stress corrosion cracking occurs rapidly in steels and certain
copper containing materials.
A) True
B) False
B
Biological corrosion is caused by (select all that apply)
1) bacteria boring into the metal surface and laying their eggs.
2) the generation of hydrogen sulphide caused by the bacteria.
3) bacteria eating the metal surface for food, as it multiplies
every 20 minutes.
4) increased oxygen generated by the bacteria at or near the
surface of the material.
5) the generation of gases that make the water more acidic, and
therefore more corrosive.
A) 2, 3, 4
