Question

The iron loss of a transformer at 400 Hz is 10
W. Assuming that eddy current and hysteresis
losses vary as the square of flux density, the
iron loss of the transformer at rated voltage but
at 50 Hz would be........ watt.​

Answer 1

Answer:

The iron loss of a transformer at 400Hz is 10w. Assuming that eddy current and hysteresis losses vary as the square of flux density, what would be the iron losses of the transformer at rated voltage but at 50Hz?

At 50 Hz a real transformer that was designed for 400 Hz would saturate. No point in calculating the magnetic losses as the transformer would be so saturated that huge currents would flow in the winding and resistive losses would dominate. If we make the assumption that the source could supply enough current to maintain the voltage despite the low impedance of the saturated transformer, the windings would probably get so hot the insulation burns and the windings short. Fire and smoke would occur.

If this is a homework question that assumes for the sake of making the calculation that the core can reach unlimited flux levels without saturating, well, you should do your own homework.

Answer 2

A actual transformer intended for 400 Hz would overload at 50 Hz.

 There's no point in estimating magnetic losses since the transformer will be so saturated that large currents will flow through the wound and resistive losses will take precedence. If we assume that the source can deliver enough current to sustain the voltage despite the saturated transformer's low impedance, the windings will most likely become so hot that the insulating melts and the windings short. There would be fire and smoke.