Transformer with secondary shorted when applied DC pulse what will secondary terminal voltage. Will this be same as that of sinewave?
Will Voltage requirement for rated current to flow in that case will be reduced 50 times (if f= 50hz)?

 

Assumption:
The transformer is a linear system.
No saturation.

A non sinusoidal input can be expressed a a sum of sinusoidals according to fourier.

Then the output is the sum of all transformed sinusoidal inputs.

See:
http://en.wikipedia.org/wiki/Fourier_series
It might be a sufficient approximation to take the first 4-6 frequencies from the fourier series.