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






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






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






4. both coils in this core are heavily insulated






5. What is a rotation meter?






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






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






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






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






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






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






12. 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






13. Autotransformers are not safe when they supply a _____ voltage from a high voltage source.






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






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






16. 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






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






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






19. Is concentrated in the metal core






20. The 3 principle components of a transformer






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






22. A ___________ transformer is a continuously adjustable Autotransformer.






23. The current related to turns ratio law






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






25. The output side it develops AC by electromagnetic mutual induction - Secondary voltage is induced in this coil






26. 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.






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






28. A single electrical circuit.






29. A transformer loses less than _% in energy






30. What does transformer efficiency mean?






31. The formula for the current related to voltage law






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






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






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






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






36. Modern; extremely efficient-more effective coupling between primary and secondary coils; smaller and lighter






37. Used to increase the magnetic flux in a transformer






38. 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






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






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






41. Copper loss is known as _____ loss.






42. A simple design has a core within each coil






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






44. 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.






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






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






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






48. 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






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






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