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A review of key concepts in power engineering 4a, focusing on multiple-choice questions and answers. It covers topics such as computer components, steam distribution, pressure reducing valves, water cycle, electrical potential, piping connections, boiler efficiency, and more. Designed to help students prepare for a test in power engineering 4a.
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The main component of any computer is the:
Select one:
a. Central processing unit
b. Memory
c. Screen
d. Keyboard ✔✔A
Which of the following statements about steam distributing heating coils is true?
Select one:
a. The coils are freeze-proof
b. The coils distribute steam evenly over the entire coil
c. The coils are used when steam cannot be throttled
d. The coils cannot be used where freezing air temperatures are frequently encountered over the coil
e. The coils can only have same end connections ✔✔B
In order to ensure safe and continuous operation of a pressure reducing valve, the valve station should have _________________.
Select one:
a. A safety valve on the high-pressure side
b. A bypass line, plus a safety valve and pressure gauge on the low-pressure side
c. Thermometers on the inlet and outlet piping
d. A strainer immediately downstream of the valve ✔✔B
In the water cycle, respiration and transpiration are:
Select one:
a. physical reactions
b. metaphysical functions
c. biological functions
d. mammalian reactions ✔✔C
If an electrical _____ is placed across a conductor, the electrons will drift from the negative end towards the positive end of the conductor.
Select one:
a. Potential
If a body travels 850m in 34 seconds, what will its average velocity be, in km/h?
Select one:
a. 25
b. 900
c. 90
d. 215 ✔✔C
One disadvantage of using threaded connections to join pipes and fittings is that it:
Select one:
a. difficult to insulate
b. Requires the services of a pipe fitter
c. is more costly
d. Weakens the pipe ✔✔D
A boiler furnace releases 10 400 kJ of heat for each kg of fuel burned and produces dry saturated steam at 14 000 kPa abs. from feedwater at 200°C. How many kg of steam will be produced for each kg of fuel burned if the boiler has an efficiency of 66%?
Select one:
a. 3.
b. 3.
c. 4.
d. 5.
e. 6.854 ✔✔B
A block and tackle system has 3 pulleys in each of two blocks. If a downward effort of 100 N is applied and the machine has an efficiency of 83.6%, what is the maximum mass that can be lifted?
Select one:
a. 501.6 kg
b. 51.1 kg
c. 5113.1 kg
d. 250 kg ✔✔B
Unit heaters differ from convectors in that they use _____ to increase heat transfer.
Select one:
a. Metal fins
b. Natural circulation
c. Blowers
Select one:
a. Equal to the schedule number
b. Larger than the outside diameter of standard weight pipe
c. The same as the outside diameter of standard weight pipe
d. Dependent on the material selected ✔✔C
The main purpose of the Boiler and Pressure Vessel Code is:
Select one:
a. To promote qualified training for operators
b. To promote efficient boiler operation
c. To protect life and property
d. The promotion of efficient combustion ✔✔C
When tightening the bolts on a pipe flange:
Select one:
a. Use a sequential criss-cross method of tightening
b. The top bolts must be tightened first
c. The gasket should be held in place by gasket glue
d. Tighten every second bolt first, then tighten the others ✔✔A
The force of friction is:
Select one:
a. Not affected by the area of the two surfaces in contact.
b. Applied in the vertical direction.
c. Not affected by the roughness of the two surfaces in contact.
d. Dependent on the area of the two surfaces in contact. ✔✔A
A cyclone separator in a boiler steam drum:
Select one:
a. Discharges water into the scrubbers
b. Is located at the superheater outlet
c. Causes impurities to be thrown from the boiler water
d. Removes moisture from steam, using centrifugal force ✔✔D
When chromium is added to alloy steel, it:
Select one:
Carbon Dioxide is used to fight electrical fires because it
Select one:
a. Has better cooling ability than other agents.
b. Provides a barrier between the oxygen and the burning components.
c. Does not leave a residue.
d. Is non toxic. ✔✔C
Carbon that is not combined with hydrogen is referred to as:
Select one:
a. Mono-carbon
b. Separated carbon
c. Free carbon
d. Fixed carbon ✔✔D
Flat-finned surface type coils are normally used for:
Select one:
a. Steam heating purposes
b. Water heating purposes
c. High temperature application
d. Low temperature application where ice may form
e. Greater turbulence of air at the fin surface ✔✔D
The three most common views used in drawings are the front, _______________ and _____________ views:
Select one:
a. Plan, side
b. Plan, bottom
c. Bottom, side
d. Back, side ✔✔A
In a low-pressure serpentine watertube boiler, the tubes are attached by either _______ or by using ferrules.
Select one:
a. Seamless fittings
b. Threading
c. Expanding
The ratio between the ultimate strength and the allowable stress is called the:
Select one:
a. Working stress
b. Safety factor
c. Maximum allowable load
d. Ultimate stress ✔✔B
In the ecosystem, green plants are considered to be:
Select one:
a. Consumers
b. Inactive matter
c. Decomposers
d. Producers ✔✔D
In the process of making iron, limestone is added to:
Select one:
a. Make the pig iron more malleable
b. The blast furnace in order to form slag
c. The iron ore in the moulds
d. Pig iron moulds ✔✔B
The basic food source for all organisms is:
Select one:
a. fungi
b. plankton
c. microorganisms
d. plants ✔✔D
Large capacity burners:
Select one:
a. must not have full flow of fuel on startup
b. Are very safe relative to puff-back
c. Require only a small pilot flame
d. Require high flow on ignition ✔✔A
During the rehabilitation of an injured worker, the supervisor should:
d. corrective, adaptive, restorative ✔✔B
What is "respiration"?
Select one:
a. the process where plants take in carbon dioxide
b. the process where animals exhale
c. the process where animal life takes in oxygen
d. the process where oxygen is recycled in the environment ✔✔C
A device that normally uses air or steam to do its job is the:
Select one:
a. Siphon
b. Operating control
c. Burner
d. Soot blower ✔✔D
In order to produce greater efficiency, higher boiler pressures were used and this led to _____ due to employing of unqualified operators in a power plant.
Select one:
a. Economic gains
b. Serious accidents
c. Higher efficiency
d. Safer working conditions ✔✔B
Find the force required to start a 1 tonne object moving along a surface with a coefficient of friction of 0.62.
Select one:
a. 9810 N
b. 6082.2 N
c. 620 N
d. 6.1 N. ✔✔B
Pressure controllers can be divided into two classes:
Select one:
a. High and low voltage
b. High and low flow
Which of the following extinguishers would ordinarily be used to combat a Class "C" fire:
Select one:
a. Carbon dioxide and Foam
b. Carbon dioxide and Dry chemical
c. Foam and Dry chemical
d. Foam and Water ✔✔B
Arc welding produces:
Select one:
a. an adhesive reaction between the metals
b. a puddle of molten metal at the electrode tip
c. a weld which has inferior metal properties than the parent metals
d. no splatter, and minimal ultraviolet energy ✔✔B
The output of an immersion type electric boiler is controlled by __________ one or more elements as required.
Select one:
a. controlling the basket level of
b. immersing
c. short-circuiting
d. turning the power on or off ✔✔D
When a modulating mechanical atomization system is used with an oil burner:
Select one:
a. Air pressure at the burner should be 70 kPa
b. Dry saturated steam should be used
c. Very high pump pressure is required for correct atomization
d. The fuel must be preheated to 90 degrees C ✔✔C
In an electrostatic precipitator the:
Select one:
a. Particles receive a positive charge
b. Collector plates and electrodes are both positively charged
c. Discharge electrode is negatively charged
d. Ash falls unaided into the bottom hopper ✔✔C