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






2. How coercivity is minimized






3. The number of turns can be adjusted in these types of transformers






4. The 3 principle components of a transformer






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






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






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






8. An instrument used to measure electrical current.






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






10. 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






11. What does transformer efficiency mean?






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






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






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






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






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






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






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






19. 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






20. The formula for the current related to voltage law






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






22. The 4 types of transformer cores






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






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






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






26. The formula for the voltage related to turns ratio






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






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






29. Is concentrated in the metal core






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






31. Refers to the transformer's ability to avoid power loss (heat)






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






33. A simple design has a core within each coil






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






35. Copper loss is known as _____ loss.






36. The current related to turns ratio law






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






38. 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)






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






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






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






42. 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






43. A transformer loses less than _% in energy






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






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






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






47. To minimize ________ in transformer construction - the primary and secondary windings are placed on the same leg(s) of the core.






48. 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






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






50. A ___________ transformer is a continuously adjustable Autotransformer.