2A652 Vol 3 CDC Ure 2015
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- 1.To change electrical energy to mechanical energy is the purpose of a
- A.
Generator.
- B.
Converter.
- C.
Inverter.
- D.
Motor.
- 2.Electrical contact between the stationary and rotating parts of a motor is the function of the
- A.
Field windings.
- B.
Commutator.
- C.
Bearings.
- D.
Brushes.
- 3.Torque is defined as
- A.
Wattage.
- B.
Horsepower.
- C.
Rotational force.
- D.
Opposition to applied voltage.
- 4.In a series-wound direct current (DC) motor, speed is dependent on the
- A.
Load.
- B.
Torque.
- C.
Armature.
- D.
Field winding.
- 5.The relationship between slip and torque can best be described as more
- A.
Torque causing more slip.
- B.
Slip causing more torque.
- C.
Torque causing less slip.
- D.
Slip causing less torque.
- 6.The three-phase induction motor does not require
- A.
Slip.
- B.
A rotor.
- C.
A stator.
- D.
A starting device.
- 7.To reverse the direction of rotation of a three-phase inductive motor, you must reverse
- A.
All three phases.
- B.
Any two power leads.
- C.
A and B phases only.
- D.
B and C phases only.
- 8.The stator windings of a synchronous motor are spaced
- A.
20 degrees apart.
- B.
30 degrees apart.
- C.
90 degrees apart.
- D.
120 degrees apart.
- 9.The rotation speed of a synchronous motor is controlled by the
- A.
Load.
- B.
Torque.
- C.
Input frequency.
- D.
Armature current.
- 10.During an inspection of a direct current (DC) motor, check the brushes for
- A.
Pitting.
- B.
Seating.
- C.
Coloration.
- D.
Brittleness.
- 11.When you check the concentricity of a commutator or slip rings, look for
- A.
Wear.
- B.
Pitting.
- C.
Roundness.
- D.
Overheating.
- 12.When using a troubleshooting chart, what are you not likely to find?
- A.
Analysis.
- B.
Remedies.
- C.
Symptoms.
- D.
Probable causes.
- 13.Most troubleshooting on a motor can be done using a
- A.
Megger.
- B.
Growler.
- C.
Multimeter.
- D.
Clamp-on ammeter.
- 14.Perform an operational check of the unit
- A.
At the last minute.
- B.
With the defective part removed.
- C.
Before final reassembly of the enclosure.
- D.
As soon as you replace the defective part.
- 15.The component most likely to be damaged by poorly filtered fuel is the
- A.
Combustion chamber.
- B.
Transfer pump.
- C.
Fuel lines.
- D.
Injectors.
- 16.The type of injector that is operated by a rocker arm is
- A.
Spray.
- B.
Pintle.
- C.
Pressure.
- D.
Mechanical.
- 17.Aside from idle speed, the limiting speed governor through the use of flyweights and spring tension controls
- A.
Load speed.
- B.
Minimum speed.
- C.
Maximum speed.
- D.
Intermediate speed.
- 18.A lubricant performs which function when it deposits particles of dirt in the oil sump?
- A.
Cooling.
- B.
Sealing.
- C.
Cleaning.
- D.
Reducing friction.
- 19.What component holds a large amount of coolant in close contact with a large volume of air?
- A.
Radiator cap.
- B.
Thermostat.
- C.
Water pump.
- D.
Radiator.
- 20.Which liquid cooling system component circulates the coolant?
- A.
Vacuum valve.
- B.
Water pump.
- C.
Cooling fan.
- D.
Radiator.
- 21.One of the impellers within a blower on a diesel engine is normally driven
- A.
By the engine electrical system through a DC motor.
- B.
By the engine exhaust gases flowing across the turbine wheel.
- C.
From the engine crankshaft through a system of gears or a silent chain.
- D.
Through a solid shaft connected between the blower and the transmission.
- 22.What must be accomplished to supercharge a diesel engine?
- A.
Change the overlap and timing so that the intake and exhaust valves are not open at the same time.
- B.
Change the overlap and timing so that the intake and exhaust valves are open at the same time.
- C.
Advance exhaust valve opening time.
- D.
Retard intake valve opening time.
- 23.The filtration step protects the diesel engine fuel system from
- A.
Blockage of airflow.
- B.
Lube system malfunctions.
- C.
Slipping belts on the blower.
- D.
Abrasion by foreign particles.
- 24.The best step in preventing abnormal amounts of carbon, moisture, and sludge buildup in a diesel engine, is to
- A.
Avoid operating the engine for extended periods at no-load.
- B.
Operate the unit at idle speed for long periods of time.
- C.
Drain moisture from fuel system periodically.
- D.
Perform a preoperational check.
- 25.When performing a compression test, measuring pounds per square inch (psi), the maximum allowable deviation between cylinders is
- A.
25 psi.
- B.
50 psi.
- C.
75 psi.
- D.
100 psi.
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