ELECTRICIAN 1st YEAR MODULE -Transformer July 2, 2025June 30, 2025 by admin TRANSLATE THIS QUIZ IN YOUR LANGUAGE इस प्रश्नोत्तरी का अपनी भाषा में अनुवाद करें <<1234567891011121314151617181920212223242526272829303132333435>> 0% Question 1 of 35 1. Why are ferrite cores used in radio receivers? Reduce electric interference Reduce constant losses Improve sound quality Increase receiver efficiencyQuestion 1 of 35Question 2 of 35 2. What condition gives maximum transformer efficiency? Copper loss > Iron loss Copper loss = Iron loss Copper loss < Iron loss Copper loss = Eddy current lossQuestion 2 of 35Question 3 of 35 3. What is the relationship between primary voltage (E1 V1 ) and secondary voltage (E2, V2) in an ideal transformer? E1 = V1 and E2 = V2E1 < V1 and E2 < V2E1 > V1 and E2 > V2E1= V1 and E2 = V2Question 3 of 35Question 4 of 35 4. What type of transformer is this? Audio frequency transformer Shell type transformer Core type transformer Auto transformerQuestion 4 of 35Question 5 of 35 5. Which type of transformer is used for high frequency applications? Ring core transformer Silicon steel core transformer Ferrite core transformer Grain oriented core transformerQuestion 5 of 35Question 6 of 35 6. Which transformer measures high voltage installations? Pulse transformers Ignition transformers Constant voltage transformers Potential transformersQuestion 6 of 35Question 7 of 35 7. How is copper loss determined in transformers? Open circuit test Short circuit test Ratio test Impulse testQuestion 7 of 35Question 8 of 35 8. Which loss is assessed by open-circuit test? Hysteresis loss only Eddy current loss only Copper loss Core lossQuestion 8 of 35Question 9 of 35 9. Which transformer loss is determined by short circuit test? Eddy current loss Copper loss Windage loss Hysteresis lossQuestion 9 of 35Question 10 of 35 10. Why does a current transformer core have low reactance and low core losses? To prevent high static shield To minimize the burden To maintain constant output To minimize reading errorsQuestion 10 of 35Question 11 of 35 11. Which cooling method is used in pole-mounted distribution transformers? Oil natural air natural Oil natural air blast Air natural Oil forced air forcedQuestion 11 of 35Question 12 of 35 12. Calculate the voltage regulation percentage if no-load voltage is 240V and full-load voltage is 220V: 8.71% 9.09% 8.30% 7.20%Question 12 of 35Question 13 of 35 13. What type of EMF is induced in an ideal two-winding transformer? Dynamically induced EMF Statically induced EMF Self induced EMF Mutually induced EMFQuestion 13 of 35Question 14 of 35 14. What material is used in breathers to prevent moisture in transformer oil? Sodium chloride Ammonium chloride Charcoal-salt mixture Silica gelQuestion 14 of 35Question 15 of 35 15. Why is load disconnected before OFF-load tap changing? Disconnect diverter moving contact Provide electrical isolation for windings Avoid heavy sparking at contacts Disconnect tappings from neutralQuestion 15 of 35Question 16 of 35 16. Why are distribution transformers typically delta-primary and star-secondary? Reduce transformer losses Maintain constant voltage Facilitate 3-phase 4-wire distribution Avoid overloadingQuestion 16 of 35Question 17 of 35 17. What is the disadvantage of auto transformers? Heavier weight Cannot isolate secondary winding More losses Poor voltage regulationQuestion 17 of 35Question 18 of 35 18. What activates the top float switch in a Buchholz relay? Open circuit condition High temperature condition Overloading condition Moisture presenceQuestion 18 of 35Question 19 of 35 19. What is the function of Buchholz relay in power transformers? Protection from high temperature Protection from overloading and short circuits Protection from moisture in oil Protection from tank pressureQuestion 19 of 35Question 20 of 35 20. Why is the primary of a potential transformer wound with thin wire and many turns? To obtain required voltage ratio To regulate primary current To offer high inductance To stabilize input/output voltageQuestion 20 of 35Question 21 of 35 21. How can potential transformer reading errors be reduced? Using thin laminated core Using good quality core material Providing long magnetic path Using high flux density materialQuestion 21 of 35Question 22 of 35 22. What is the cooling method of transformers? Oil forced air forced cooling Oil natural air forced cooling Oil natural water forced cooling Oil natural coolingQuestion 22 of 35Question 23 of 35 23. Why are laminated cores used in transformers? Reduce copper loss Reduce eddy current loss Reduce mechanical loss Reduce hysteresis lossQuestion 23 of 35Question 24 of 35 24. What does the crackle test of transformer oil determine? Dielectric strength Moisture Viscosity AcidityQuestion 24 of 35Question 25 of 35 25. What is the advantage of stepped core in large transformers? Minimizes copper use Reduces eddy current loss Reduces hysteresis loss Reduces core spaceQuestion 25 of 35Question 26 of 35 26. What type of transformer is this? Ferrite core transformer Ring core transformer Iron core transformer Air core transformerQuestion 26 of 35Question 27 of 35 27. What is absolutely essential for parallel transformer operation? Phase sequence Insulation class Type of cooling Nature of loadQuestion 27 of 35Question 28 of 35 28. How is moisture controlled in transformer breathers? Transformer oil Silica gel Sodium chloride Ammonium jellyQuestion 28 of 35Question 29 of 35 29. Which construction technique reduces copper loss in large transformers? Reduced core thickness Stepped core arrangement Grain oriented core Laminated coreQuestion 29 of 35Question 30 of 35 30. Which material is used to make the core of power transformers? Rolled steel Copper alloy Cold rolled grain oriented steel Soft ironQuestion 30 of 35Question 31 of 35 31. What is the purpose of tap changing in power transformers? Optimize for maximum efficiency Change distribution voltage ratio Maintain secondary voltage Maintain primary voltageQuestion 31 of 35Question 32 of 35 32. What is the function of a conservator in a transformer? Allows oil expansion due to load variation Transfers heat to atmosphere Releases internal pressure Prevents moisture entryQuestion 32 of 35Question 33 of 35 33. What is the composition of silicon steel in transformer cores? 97% steel, 3% silicon 90% steel, 10% silicon 93% steel, 7% silicon 95% steel, 5% siliconQuestion 33 of 35Question 34 of 35 34. What is the purpose of an explosion vent in power transformers? Moisture releasing Air releasing Heat releasing Pressure releasingQuestion 34 of 35Question 35 of 35 35. What is this power transformer component called? Buchholz relay Explosion vent Breather Tap chargerQuestion 35 of 35 Loading...
