The meaning of a star-delta connected transformer in a zero sequence network of a 3-Phase power system is justified interims of its primary and secondary side with respect to the ground as

A message to be transmitted using AM is given by m(t): = 4 cos 400πt + 3 cos 300πt where the unit of time is milliseconds. It is to be sent using a carrier frequency of 30 kHz. a) What is the message bandwidth? b) Sketch its magnitude spectrum, clearly specifying the units used on the frequency axis. c) For a modulation index of 50%, write an explicit time domain expression for the AM signal. d) What is the power efficiency of the AM signal? e) Sketch the magnitude spectrum for the AM signal, again clearly specifying the units used on the frequency axis.

3.8. Three identical 9-MVA, 7.2-kV/4.16-kV, single-phase transformers are con- nected in wye on the high-voltage side and delta on the low voltage side. The equivalent series impedance of each transformer referred to the high-voltage side is 0.12 + j0.82 S per phase. The transformer supplies a balanced three- phase load of 18 MVA, 0.8 power factor lagging at 4.16 kV. Determine the line-to-line voltage at the high-voltage terminals of the transformer.

TRUE or FALSE: Delta-wye configuration of three-phase transformer is best suited for step-up applications.