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akch2002, Engineer
Category: Homework
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Experience:  Home work expert
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When youre taking a PM motor apart you should exercise special

Resolved Question:

When you're taking a PM motor apart you should exercise special care not to damage the

A. end bells.

B. commutator.

C. permanent magnets.

D. brush holders.

2. Which one of the following motor types uses permanent magnets in the armature or rotor?

A. Stepper motor

B. PM motor

C. PM servo motor

D. Pancake motor

3. The magnetic material that's placed inside a coil of wire in a motor is called a

A. pole.

B. concentrator.

C. form.

D. rod.

4. As you walk up to a machine, you see a technician tapping on the back section of a DC motor with a lead mallet. This technician is

A. cleaning the commutator.

B. looking for weak or worn brushes.

C. checking for end bell cracks.

D. reseating the rear end bell on the case.

5. What type of motor has the same wire diameter in both the field and the armature coils?

A. Series-wound

B. Interpole-wound

C. Shunt-wound

D. Compound-wound

6. The large current that a DC motor will draw on start-up is called

A. velocity current.

B. dynamic current.

C. inrush current.

D. acting current.

7. The opposition to the flow of magnetic flux is called

A. resistance.

B. friction.

C. reluctance.

D. magnomotive force.

8. A DC motor that has interpoles will have the interpole windings in

A. series with the field windings.

B. parallel with the field windings.

C. series with the armature.

D. parallel with the armature.

9. If the field windings of a 50/100 VDC motor are connected to a 100 VDC source of power, the field windings should be connected in

A. series with each other.

B. parallel with each other.

C. series with the armature.

D. parallel with the armature.

10. The energy that's lost in a DC motor is rather small. Most of the energy is lost as

A. stray magnetic fields.

B. friction in the bearings.

C. windage losses inside the motor.

D. heat losses to the case.

11. There are two wires labeled P1 and P2 at a DC motor's junction box. These wires will attach to what internal component of the motor?

A. Ground

B. A thermostat

C. The parallel winding

D. A speed potentiometer

12. The letters CEMF are used to describe

A. centrifugal forces within a motor.

B. countervoltages and currents created within a motor.

C. critical winding currents that should not be exceeded.

D. the portion of the supplied current that is converted to heat.

13. The major failure area of a typical wound-field and wound-armature DC motor is

A. open field windings.

B. brush wear and failure.

C. bearing failure.

D. a faulty commutator segment.

14. A normal commutator will have which one of the following colors where the brushes contact the commutator?

A. Black

B. Chocolate-brown

C. Slate-gray

D. Auburn-brown

15. A PM field servo motor may be equipped with a resolver that is used to

A. excite the armature windings.

B. prevent the brushes from sparking.

C. feed back position information.

D. create a voltage that increases with velocity.

16. One common type of electronic circuit component that is used to control the voltage and current to a DC motor is the

A. resistor.

B. silicon-controlled rectifier.

C. diode.

D. capacitor.

17. An encoder is a device that is used to

A. commutate the field windings.

B. feed pack position information.

C. reduce brush sparking.

D. excite the motor's interpoles.

18. When field voltage is controlled to provide a method of variable speed control, the system is using a concept known as field

A. weakening.

B. bias.

C. stability.

D. drive.

19. If an electronic control system is starting a motor, it will keep start-up current within limits by using

A. a rheostat and a relay.

B. a pulsed diode control.

C. an acceleration ramp.

D. coast-up system.

20. Which one of the following types of motors can be powered with either AC or DC electricity?

A. Shunt-wound motor

B. Servo motor

C. Universal motor

D. Pancake motor

21. The magnets that are used in the field of a quality DC PM motor are made from

A. rare-earth material.

B. magnetized steel.

C. natural magnets.

D. special aluminum-nickel compounds.

22. Which one of the following types of motors is not normally reversible?

A. Servo motor

B. PM motor

C. Universal motor

D. Brushless DC motor
Submitted: 4 years ago.
Category: Homework
Expert:  akch2002 replied 4 years ago.
Thanks. I will look into these questions if I can reply.
Expert:  akch2002 replied 4 years ago.

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akch2002, Engineer
Category: Homework
Satisfied Customers: 3099
Experience: Home work expert
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