The hysteresis loop of a magnetic material has an area of 5 cm² with the scales given as 1 cm = 2 AT and 1 cm = 50 mWb. At 50 Hz, the total hysteresis loss is

It is desirable to eliminate 5^th harmonic voltage from the phase voltage of an alternator. The coils should be short-pitched by an electrical angle of

Figure shows the magnetization curves of an alternator at rated armature current, unity power factor and also at no load. The magnetization curve for rated armature current, 0.8 power factor leading is given by

X_d, X_d^' and X_d^" are steady stated-axis synchronous reactance, transient d-axis reactance and sub-transient d-axis reactance of a synchronous machine respectively. Which of the following statements is true?