Test your basic knowledge |

Transformers

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Insulated primary and secondary coils are in close proximity to each other - no iron core and very innefficient






2. The volt-amperes of the primary of a transformer is equal to the _____ - _____ output of the transformer.






3. Modern; used to control filament circuit; replaced both the rheostat and choke coil; operated on the electromagnetic principle that if an iron core within or near a coil is saturated with magnetic flux by an independed source of direct current - the






4. A ___________ transformer is a continuously adjustable Autotransformer.






5. both coils in this core are heavily insulated






6. The 3 principle components of a transformer






7. A partial or total local failure in the insulation or continuity of a conductor.






8. _____ shows that the voltamperes of the primary of a transformer equal the voltamperes of the secondary of a transformer.






9. Hysteresis Loss can be reduced by using a core with this feature






10. A transformer is a device that either increases or decreases alternating current and voltage using this principle






11. Central magnetic core made of






12. Copper loss is known as _____ loss.






13. A simple design has a core within each coil






14. closed core with a top and bottom. It directs the magnetic field towards the primary and secondary coils and increases the field stregnth






15. The output rating of a transformer is based upon the maximum _____ the transformer is capable of carrying without exceeding a certain temperature rise.






16. Both the primary and secondary coils in a transformer are arranged around this






17. Anything above 600 volts is _____?






18. Some losses occur in all transformers. These losses are classified as copper losses and _____ losses.






19. What does transformer efficiency mean?






20. _____ shows that the voltages across the windings of a transformer are directly proportional to the turns in each winding.






21. The transformer winding to which voltage is supplied is called the _____ winding.






22. A stationary device for transferring alternating current electrical energy from one circuit to another circuit by electromagnetic means.






23. ___________ is often used in laminated cores - increases electrical resistance which decreases eddy currents






24. A transformer rated at 500KVA and below used for voltage transformation on the distribuition system.






25. The magnetic lines of force that flow from the north pole of a magnet and return to the south pole.






26. A transformer loses less than _% in energy






27. Instrument transformers reduce high voltages and currents to safe - usable values for the operation of _____ _____.






28. The terminals of the high voltage winding are marked _____.






29. How coils serve as the primary and secondary windings for an autotransformer






30. Is concentrated in the metal core






31. The current related to turns ratio law






32. Two coils wound on a closed iron core form a ________.






33. A transformer is a device that has no moving parts and that transfers energy from one circuit to another by _____.






34. Used to increase the magnetic flux in a transformer






35. The 3 types of transformer power loss






36. What is a rotation meter?






37. The turns ratio between the windings (primary & secondary) of a transformer unless otherwise specified.






38. Reference to a jumper or conductor - to or from a piece of electrical equipment.






39. When an alternating current is applied to the high-voltage (H) winding of a transformer with no load on the secondary (X) winding - a small current - called the _____ current - flows in the primary.






40. This type of core is moderately efficient due to closing the core and layering design which reduces power loss from less leakage flux which provides a continuous path for magnetic flux and an increase in field strength






41. 3 types of transformers






42. Defined as the ratio of the power output to the power input (in a closed circuit containing resistance)






43. The total numbre of lines or force issuing from a pole. (north or south)






44. Connected to earth or to some conducting body which serves in place of the earth.






45. The energy is always transferred without a change in frequency - but usually with changes in _____ and _____.






46. Core losses are _____ loss and _____ - _____ loss.






47. A transformer which when supplied from a constant potential source automatically maintans a constant current in its secondary circuit under varying conditions of load impedance. Used on series street light circuits.






48. The winding to which the load is connected is called the _____ winding.






49. If the transformer is used as a _____ transformer - the low voltage winding is the primary.






50. A magnetic field changing with respect to the conductor will generate a _____ in the conductor.