Electrical Machines Expected MCQ PDF 10 For Coal India Limited (CIL) MT Exam 2017 - All Exam Review

1) In a 20 kVA, 2200 / 220 volts transformer iron and copper losses are 300 and 400 watts respectively. Its efficiency at half load and unity power factor is a. 95.11% b. 96.15% c. 97.77% d. 98% ANSWER: 96.15% 2) A 500 kVA single phase transformer has 90% efficiency at both half load and full load at unity power factor. Then iron losses will be a. 12.55 KW b. 13.55 kW c. 16.55 kW d. 18.55 KW ANSWER: 18.55 KW 3) While performing a circuit test on transformer at 30v, 30 Hz it gives Φ1 as lagging power factor. If the same