• In the case of the dark method, this is only supposed to be carried out if th incandescent lamps are not lighting up i

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In The Case Of The Dark Method This Is Only Supposed To Be Carried Out If Th Incandescent Lamps Are Not Lighting Up I 1 (87.98 KiB) Viewed 11 times

• In the case of the dark method, this is only supposed to be carried out if th incandescent lamps are not lighting up in cyclical sequence • As soon as the incandescent lamps light up in cyclical sequence the interchanging two phases is absolutely necessary 7) How do the voltages and currents respond under the various loads (Several answers may be correct)? • One can clearly see that resistive and inductive loads decrease the transformen secondary voltage • One can clearly see that resistive and inductive loads increase the transformen secondary voltage • Capacitive loads increase the output voltage • Capacitive loads decrease the output voltage 8) A (40/240) V step-up transformer is connected to a 40 V battery while the load is 80 9. Output power is: (a) 0 W (b) I W (c) 20 W (d) 80 W 9) A 30 induction motor is running at 720 rpm. Its number of poles is: (a) 4 (b) 6 (c) 8 (d) 10 10) The open-circuit test in a transformer is used to measure (a) Copper loss (b) Winding loss (c) Total loss (d) Core los 11) For a transformer with number of secondary windings more than the number of primary windings, the secondary current will be (a) More than the primary current (b) Less than the primary current (c) Equal to the primary current (d) Zero 12) If a transformer has 50 turns in the primary winding and 10 turns in the secondary winding, what is the reflective resistance if the secondary load resistance is 250? (a) 250 (b) 25 (c) 6250 (d) 62500 Question 2: [8 Marks] A three-phase transformer bank is to handle 600 KVA and have a 34.5/13.8-kV voltage ratio. Find the rating of each individual transformer in the bank (high voltage, low voltage, turns ratio, and apparent power) if the transformer bank is connected to (a) Y-Y, (b) Y-A, (C) A-Y. (d) A-A. Connection Primary Voltage Secondary Voltage Apparent Power Turns Ratio Y-Y Y.al A-Y Δ-Δ