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






2. The terminals of the low voltage winding are marked _____.






3. Waste of power known as transformer loss - often produced by closed-ended core






4. Divergence of the magnetic field causes this






5. It refers to the direction of current flow in a closed circuit.






6. The simplest type of transformer core






7. 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.






8. With no load on the secondary winding - a small current flows in the primary called _____ _____.






9. A large amount of power wasted with the open-ended core






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






11. 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






12. The input side that attaches to the AC supply it recieves the electrical energy or incoming voltage






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






14. The voltage induced in the coil is directly proportional to this






15. The entire transformer is placed in a metal tank then immersed in ________.






16. What is a rotation meter?






17. What does transformer efficiency mean?






18. A test instrument used to indicate low voltage potentials in the range of 110 to 600 volts either alternating or direct current. (slang term: wiggy)






19. A system of conductors in which at least one conductors or point (usually the middle wire or neutral point of a transformer or generator windings) is intentionally grounded either solididly or through a current-limiting device.






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






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






22. The transformer winding to which the load is connected is called the _____ winding.






23. An electromagnetic device that operates on the principle of self induction. It uses AC.






24. A magnet made by winding a coil of wire around a soft iron core. Current passed through this winding produces magnetic lines of force in the coil.






25. The formula for the voltage related to turns ratio






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






27. The loss of power required to reverse the core magnatism each time the current reverses. This loss is caused by friction between the molecules of iron as these particles are aligned first in one direction and the in the opposite direct as current dir






28. The capacity of a transformer is rated in ____ _____.






29. The turns of both windings are cut by the same flux; therefore the induced emf in each turn of both windings is the _____.






30. This is the most advanced and most efficient type of tansformer; it is commonly used in x-ray equipment






31. A transformer primary (H) that has 400 turns is wound to step the voltage down from 240 volts to 120 volts. The number or turns (TX) required in the secondary (X) winding is _____.






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






33. The relationship between amperage flowing through the coils and the number of turns on individual coils is inverse






34. Used to increase the magnetic flux in a transformer






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






36. A variable transformer is a continuously adjustable _____ - has the primary winding and secondary winding electrically connected.






37. has a laminated iron core (layers of metal plates)






38. The formula for the current related to voltage law






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






40. The current related to turns ratio law






41. How the voltage and the number of turns are related for the voltage related to turn ratio






42. How a variable degree of core saturation is accomplished in a saturable reactor?






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






44. The characteristic that requires energy to carry out the constant reorientation of the magnetic dipoles in the hysteresis loss






45. A ___________ transformer is a continuously adjustable Autotransformer.






46. The 4 types of transformer cores






47. Insulated primary and secondary coils are in close proximity to each other - no iron core and very innefficient






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






49. Central magnetic core made of






50. Function of the dielectric oil