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. Which transformer measures high voltage installations? Ignition transformers Pulse transformers Constant voltage transformers Potential transformersQuestion 1 of 35Question 2 of 35 2. What activates the top float switch in a Buchholz relay? Moisture presence Overloading condition High temperature condition Open circuit conditionQuestion 2 of 35Question 3 of 35 3. How is copper loss determined in transformers? Impulse test Open circuit test Short circuit test Ratio testQuestion 3 of 35Question 4 of 35 4. What type of transformer is this? Audio frequency transformer Core type transformer Shell type transformer Auto transformerQuestion 4 of 35Question 5 of 35 5. What condition gives maximum transformer efficiency? Copper loss < Iron loss Copper loss = Eddy current loss Copper loss = Iron loss Copper loss > Iron lossQuestion 5 of 35Question 6 of 35 6. What type of transformer is this? Ring core transformer Air core transformer Ferrite core transformer Iron core transformerQuestion 6 of 35Question 7 of 35 7. How can potential transformer reading errors be reduced? Using good quality core material Using high flux density material Providing long magnetic path Using thin laminated coreQuestion 7 of 35Question 8 of 35 8. What is absolutely essential for parallel transformer operation? Insulation class Type of cooling Phase sequence Nature of loadQuestion 8 of 35Question 9 of 35 9. What is the purpose of an explosion vent in power transformers? Air releasing Pressure releasing Heat releasing Moisture releasingQuestion 9 of 35Question 10 of 35 10. What is the disadvantage of auto transformers? Heavier weight Cannot isolate secondary winding Poor voltage regulation More lossesQuestion 10 of 35Question 11 of 35 11. Which material is used to make the core of power transformers? Cold rolled grain oriented steel Soft iron Copper alloy Rolled steelQuestion 11 of 35Question 12 of 35 12. Why are distribution transformers typically delta-primary and star-secondary? Reduce transformer losses Maintain constant voltage Facilitate 3-phase 4-wire distribution Avoid overloadingQuestion 12 of 35Question 13 of 35 13. What type of EMF is induced in an ideal two-winding transformer? Dynamically induced EMF Mutually induced EMF Self induced EMF Statically induced EMFQuestion 13 of 35Question 14 of 35 14. Which cooling method is used in pole-mounted distribution transformers? Oil forced air forced Oil natural air natural Oil natural air blast Air naturalQuestion 14 of 35Question 15 of 35 15. What material is used in breathers to prevent moisture in transformer oil? Sodium chloride Silica gel Ammonium chloride Charcoal-salt mixtureQuestion 15 of 35Question 16 of 35 16. How is moisture controlled in transformer breathers? Silica gel Sodium chloride Transformer oil Ammonium jellyQuestion 16 of 35Question 17 of 35 17. What is the cooling method of transformers? Oil natural air forced cooling Oil natural cooling Oil forced air forced cooling Oil natural water forced coolingQuestion 17 of 35Question 18 of 35 18. Which type of transformer is used for high frequency applications? Grain oriented core transformer Ferrite core transformer Ring core transformer Silicon steel core transformerQuestion 18 of 35Question 19 of 35 19. Why does a current transformer core have low reactance and low core losses? To prevent high static shield To maintain constant output To minimize reading errors To minimize the burdenQuestion 19 of 35Question 20 of 35 20. Which loss is assessed by open-circuit test? Eddy current loss only Hysteresis loss only Copper loss Core lossQuestion 20 of 35Question 21 of 35 21. Calculate the voltage regulation percentage if no-load voltage is 240V and full-load voltage is 220V: 7.20% 9.09% 8.71% 8.30%Question 21 of 35Question 22 of 35 22. What does the crackle test of transformer oil determine? Acidity Viscosity Dielectric strength MoistureQuestion 22 of 35Question 23 of 35 23. What is the function of Buchholz relay in power transformers? Protection from moisture in oil Protection from tank pressure Protection from overloading and short circuits Protection from high temperatureQuestion 23 of 35Question 24 of 35 24. 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 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. Why are ferrite cores used in radio receivers? Improve sound quality Reduce electric interference Reduce constant losses Increase receiver efficiencyQuestion 26 of 35Question 27 of 35 27. What is the function of a conservator in a transformer? Prevents moisture entry Transfers heat to atmosphere Releases internal pressure Allows oil expansion due to load variationQuestion 27 of 35Question 28 of 35 28. Which transformer loss is determined by short circuit test? Windage loss Copper loss Hysteresis loss Eddy current lossQuestion 28 of 35Question 29 of 35 29. What is the composition of silicon steel in transformer cores? 93% steel, 7% silicon 90% steel, 10% silicon 95% steel, 5% silicon 97% steel, 3% siliconQuestion 29 of 35Question 30 of 35 30. 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 30 of 35Question 31 of 35 31. Why is the primary of a potential transformer wound with thin wire and many turns? To obtain required voltage ratio To offer high inductance To regulate primary current To stabilize input/output voltageQuestion 31 of 35Question 32 of 35 32. What is the purpose of tap changing in power transformers? Maintain secondary voltage Change distribution voltage ratio Optimize for maximum efficiency Maintain primary voltageQuestion 32 of 35Question 33 of 35 33. Why are laminated cores used in transformers? Reduce hysteresis loss Reduce mechanical loss Reduce copper loss Reduce eddy current lossQuestion 33 of 35Question 34 of 35 34. Which construction technique reduces copper loss in large transformers? Grain oriented core Stepped core arrangement Reduced core thickness Laminated coreQuestion 34 of 35Question 35 of 35 35. What is this power transformer component called? Explosion vent Breather Tap charger Buchholz relayQuestion 35 of 35 Loading...
