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 the load is connected is called the _____ winding.






2. To prevent injury to personnel when servicing any equipment connected to a current transformer - the secondary winding must be ____ - _____.






3. Function of the dielectric oil






4. Transformers with 4800 volt primaries and 120/240 volt secondaries - either pole or subway type - with two secondary windings terminating at internal links which provide for parallel operation of the secondary windings at 120 volts or series operatio






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






6. The output which can be delivered for the time specified at rated secondary voltage and rated frequency without exceeding the specified temperature limitations.






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






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






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






10. What is a rotation meter?






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






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






13. Provides the ratio between the applied primary voltage and the induced secondary voltage as result of the turns ratio






14. The relationship between current and voltage in the coils are inverse






15. Divergence of the magnetic field causes this






16. 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.






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






18. In a transformer the _____ current will always flow in such a direction that its magnetizing action will oppose the magnetizing action of the primary winding.






19. A ___________ transformer is a continuously adjustable Autotransformer.






20. Transformer losses are classified as _____ and _____.






21. An abnormal connection of relative low resistance - whether made accidentally or intentionally - between two point of different potential in a circuit.






22. 3 types of transformers






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






24. This core is more efficient than the air core because the iron core in each coil intensifies the magnetic flux in both primary and secondary coils when they become magnetized as current flows through each set of coils






25. Transformers designed for 4800 volt primary operation - but the secondaries are connected 240/480 volts. Winding ratio is 10:1






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






27. A simple design has a core within each coil






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






29. The 3 principle components of a transformer






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






31. The 3 types of transformer power loss






32. Current flows through the primary winding in response to primary voltage and sets up a magnetic field that varies in direction and stregnth. under the influence of the changing magnetic field an AC voltage/kv is induced across the secondary coil by e






33. Determines if the transformer is a step up or step down transformer






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






35. The winding of a transformer to which electrical energy is supplied.






36. both coils in this core are heavily insulated






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






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






39. Anything above 600 volts is _____?






40. 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.






41. An instrument used to measure electrical current.






42. The shape of the core of the transformer ensures a ______________ for the magnetic flux with maximum concentration within the core and minimum leakage of the air






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






44. _____ currents are reduced by laminating the core.






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






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






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






48. Kind of wire is the secondary coil in a transformer






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






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