Free Flashcards about AC Theory ch 30 (2024)

Search » All » Unfinished » AC Theory ch 30

Help

Options

focusNode

Understanding How the DC Generator Works

Question	Answer
1. A generator is a device that converts ____ energy into ___ energy	mechanical electrical
2. What happens when a conductor cuts magnetic flux lines?	Voltage is induced into the conductor
3. DC generators operate on the principle of ___	electromagnetic induction
4. Explain, according to Flemings Generator Rule, the meaning of the extended digits. Label what each digit represents.	thumb = thrustpointer= point of fieldmiddle finger = current
5. How much voltage is being produced when the rotating conductor is parallel to the magnetic flux lines?	zero
6.Maximum voltage is induced into a conductor when it cuts the magnetic field at ___ degrees.	90 degrees (? page 225 in text)
7. ___ voltage is induced into the conductor when the loop is at 0degrees, 180, and 360 in relation to the field.	zero
8. When a conductor loop is continuously rotated in a magnetic field, the ___ output voltage follows the ___ function	AC sine
9. To convert the AC voltage from the armature to DC voltage, DC generators make use of a	commutator
10. How does a commutator cause the AC voltage that is generated appear as a DC voltage output	cuts off half the AC wave
11. When AC voltage is generated and then converted to DC voltage by use of a commutator, is the voltage a constant output?	No, it is pulsating
12. The frequency of the pulsating DC output voltage of a generator is ____ that of an AC generator	twice
13. What is the name of the rotating member of the DC generator	armature
14. What three components make up the armature	iron core, commutator, windings
15. What are the three types of armature windings found in generators.	lap wound, wave wound, and frog leg
16. The wires connected to the brushes of a generator are designated ___ and ____	A1, A2
17. ____ wound armatures are probably the most commonly used because they are designed for moderate voltages and moderate currents.	frog leg
18. ___ wound armatures are used in machines designed for low voltage and high current.	lap
19. ____ wound armatures are used in machines designed for high voltage and low current.	wave
20. What are brushes made of and why	carbon based materials because they can deal with a lot of heat
21. What is the function of pole pieces installed in the generator housing	To concentrate the magnetic field
22. What is the physical relationship between the pole pieces and the field windings in the generator	pole pieces mounted on generator. field windings wound around pole
23. Are permanent magnets ever used as the field poles in a generator	yes, they are used when the field is permanently mounted in stator
24.What are the two types of connections for generator field windings	series and shunt
25. The Series Field windings are made up of ___ (few/many) turns with large wire and the leads are labeled ___ and ____	few, S1, S2
26. How is the Shunt Field connected in a generator? How are the leads tagged?	Paralell / F1, F2
27. The Shunt Field has a ___(high/low) resistance because it is made of ____ (large/small) wire	high, small
28. When a load is connected to a series generator, the output voltage _____	increases
29. A series generator is ___ with residual magnetism	self excited
30. As additional loads are connected to a series generator, the output voltage will continue to ___ until the iron in the pole pieces and armature becomes ____	increase, saturated
31. What three factors determine the level of the output voltage of a series generator	1. strength of magnetic field produced by pole pieces.2. number of turns of wire on the armature3. speed of rotation or armature
32. Based on your answers to the two previous questions, series generators would be best used with a (constant/varying) load	constant
33. Self-excited shunt generators make use of __ to start the generation process	residual magnetism
34. The shunt type of generator provides ____ output voltage before the load is applied	full
35. As the load is increased on a shunt type generator, the output voltage will _____	decrease
36. To control the output of a shunt generator, a(n) ___ is installed to sense changes to the output current and to make adjustments to the shunt field current	electronic voltage regulator
37. compound generators make use of a(n) ___ field winding and a(n) ____ field winding.	series shunt
38. What is the primary advantage of a compound generator	overcome voltage problems
39. A long shunt compound generator has the ___ in parallel with the ___ winding and the armature	shunt winding (into larger connection point) series
40. The short shunt compound generator has the shunt field connected in parallel with the ___	armature
41. What is Cumulative Compounding	fields aid each other
42. What is Differential Compounding	oppose each other
43. In an Over-compound Generator, the load voltage is____(less than/equal to/ greater then) the no load voltage	greater
44. In an Under-Compound Generator, the load voltage is ____(less than/equal to/ greater than) the no load voltage	less than
45. In a Flat Compound Generator, the load voltage is ___(less than/equal to/ greater than) the no load voltage	equal to
46. The greatest generator loss is due to the ___ of the windings	resistance
47. Power loss due to induced currents in the core material of a generator is called ___ loss	eddie current
48. ___ loss is due to molecular friction	hysteresis
49. Almost all power losses in a generator, with the exception of flux linkage, are manifested in the form of ____	heat
50. The two primary magnetic flux fields in a generator are field flux and ___ flux	armature
51. The magnetic neutral plane will shift in the direction of the ____.	armature rotation
52. To prevent a shift in the neutral plane, ___ windings are installed in the generator to cancel the effects of self-induction in the armature.	interpole
53. When DC generators are connected in parallel, an equalizing connection is used to connect the ___ fields of the two mahines in ___ with each orther	series, parallel
54. What might happen if two DC generators are simply connected in parallel without an equalizer connection	generator will work against each other

Created by: JoshHampton

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

SPACEBAR - flip the current card

LEFT ARROW - move card to the Don't know pile

RIGHT ARROW - move card to Know pile

BACKSPACE - undo the previous action

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.