Question 591. 0.  A transformer has a resistance of2% and reactance of 4%. Its regulations at 0.8 power factor lagging a leading respectively are

Question 592. 1.  Consider the following statements : The use of Delta-connected tertiary winding in star-star connected power transformers I. makes available supply for single-phase loads.2. suppresses harmonic voltages. 3. allows flow of earth fault current for operation of protective devices 4. provides low-reactance paths for zero-sequence currents.Of the statements :

Question 593. 7.  If the secondary winding ofthe ideal transformer of the circuit shown in the given figure has 40 turns, then for maximum power transfer to the 2-ohm resistor, the number of turns required in the primary winding will be Ideal Transformer

Question 594. 8.  A 220/110V, 50 Hz single-phase transformer having a negligible winding resistances operates from a variable voltage, variable frequency supply such that Vi/f (V1 = primary applied voltage, f = source frequency) is constant. This will bring in, in the given range of frequencies.

Question 595. 2.  The equivalent resistance andequivalent reactance of a transformer are respectively 0.5 SI and 0.8 12. The voltage regulation will be zero when the load power factor is

Question 596. 3.  A symmetrical 3-phase supply is applied to theprimary terminals A1, B and C1 of the Y-Y transformer asshown in the given figure. The secondary terminals A2, B2 and C2 give a symmetrical 3-phase voltage. If the terminals H1 and H2 of phase I of the primary are reversed without changing the supply at A1, B1 and C1, thenthe phase angle between the line voltage VA2B2 and c2A2 on the secondary side will be

Question 597. 4.  For the system shown in given figure, the phase relation of current 'I' with respect to the voltage VAB is Ideal transformer

Question 598. 6. Two transformers X and Y with identical ratings and dimensions have 0.8 mm and 1.2 mm thick laminations respectively. If Rm and Xm are the magnetizing branch parameters in the equivalent circuit, then

Question 599. 8.  Three single-phase transformers, each of 100 kVA rating are connected in delta. If one of the transformers is taken out of service, the capacity of the system will be

Question 600. 7.  Hysteresis loss of a transformer designed at voltage 'V' and frequency 'f' is Ph. If the transformer is operated from a voltage `x?/' and frequency `xf' the hysteresis loss for a Steinmetz constant of 2 will be