24 The following data were obtained on a 20 kVA, 50 Hz, 2000/200 V Transformer: SCT: 60 V, 10 A, 300 W. The equivalent series resistance of the transformer, referred to the LVS, is:

Consider an ideal transformer with N1=3000andN2=1000 turns. Let winding 1 be connected to a source whose voltage is e1(t)=100(1| t |)volts for 1t1ande1(t)=0 for | t |1 second. A2- farad capacitor is connected across winding 2. Sketch e1(t),e2(t),i1(t),andi2(t) versus time t.

For an ideal transformer, the efficiency is (a) 0 (b) 100 (c) 50

A 23/230-kV step-up transformer feeds a three-phase transmission line, which in turn supplies a 150-MVA,0.8 lagging power factor load through a step-down 230/23-kV transformer. The impedance of the line and transformers at 230kVis18+j60. Determine the tap setting for each transformer to maintain the voltage at the load at 23 kV.

Consider the three single-phase two-winding transformers shown in Figure 3.37. The high-voltage windings are connected in Y. (a) For the low-voltage side, connect the windings in , place the polarity marks, and label the terminals a, b, and c in accordance with the American standard. (b) Relabel the terminals a, b, and c such that VAN is 90 out of phase with Va for positive sequence.

A 250/125 V, five kVA single-phase transformer has a primary resistance of 0.2 ohms and reactance of 0.75 ohms. The secondary resistance is 0.05 ohm and reactance of 0.2 ohms.a) Determine its regulation while supplying full load on 0.8 leading p.f.b) The secondary terminal voltage on full load and 0.8 leading p.f.Ans.: -0.4.88%; 131.1

In a transformer that has 10 times more turns on the secondary side (side 2) than on the primary side (side 1), the magnitude of the voltage/EMF across the windings on the secondary side, E₂ will be... O a.... 10 times lower than the voltage/emf on the primary side, E₁. O b.... the same as the voltage/emf on the primary side. O c.... always zero regardless of the voltage on the primary side, E₁. O d.... 10 times higher than the voltage/emf on the primary side, E₁.

The resistance and reactance of the primary winding of a 440/110 V single phase transformer are 4.4 ohm and 8 ohm respectively. The resistance and reactance of the secondary winding are 1.6 ohm and 2ohm respectively. Then find the equivalent resistance, reactance and impedance referred to the primary side.

Full calculation with any assumption needed. All sub questions please as it is all related.

The efficiency of a transformer at load 0.8 p.f. Lag is -- at load 0.8 p.f. Lead * equal less than more than none of these