Choose the correct answer of the following questions: 1. If the secondary power of a transformer is increased by 50% then the magnetic flux (p) passing in the magnetic core will: a. Increase by 50% c. Increases by 25% b. Decreases by 50% d. None of the above 2. In a A-Y connection three-phase transformer of K turn ratio, the secondary line voltage is: a. VL2 =VL1 b. V₁2 = VL1 c. VL2 = KVL1 d. V₁2 = VL1 3. Two 400kVA single-phase transformers work as V-V (open-delta) connection, supply a 1200 kVA load. The kVA supplied by each transformer is: a. 400kVA of each b. Sharing the load equally d. 300kVA of each c. 693kVA of each 4. In an auto-transformer of K transformation ratio, the power transferred inductively from the primary side to the secondary side is equal to: a. P = (1-K) Pin b. P = (K) Pin d. P = K² Pin c. P = (1+K) Pin 5. In a single-phase transformer, the percentage resistance drops is 1.0% and percentage reactance drop is 5.0%, the percentage voltage regulation when the power factor 0.8 leading is: a. 3% b. -2.2% d. 3.8% c. -3.4%

Choose the correct answer of the following questions: 1. If the secondary power of a transformer is increased by 50% then the magnetic flux (p) passing in the magnetic core will: a. Increase by 50% c. Increases by 25% b. Decreases by 50% d. None of the above 2. In a A-Y connection three-phase transformer of K turn ratio, the secondary line voltage is: a. VL2 =VL1 b. V₁2 = VL1 c. VL2 = KVL1 d. V₁2 = VL1 3. Two 400kVA single-phase transformers work as V-V (open-delta) connection, supply a 1200 kVA load. The kVA supplied by each transformer is: a. 400kVA of each b. Sharing the load equally d. 300kVA of each c. 693kVA of each 4. In an auto-transformer of K transformation ratio, the power transferred inductively from the primary side to the secondary side is equal to: a. P = (1-K) Pin b. P = (K) Pin d. P = K² Pin c. P = (1+K) Pin 5. In a single-phase transformer, the percentage resistance drops is 1.0% and percentage reactance drop is 5.0%, the percentage voltage regulation when the power factor 0.8 leading is: a. 3% b. -2.2% d. 3.8% c. -3.4%

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.9P

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