What will happen if we give DC supply to transformer?
Transformers works on Magnetic effect of Current. Since DC doesn’t have any magnetic field, they will not get step-up or down. So you will get 0 voltage at the output.
Simple, no voltage or output.
It is very simple, you will have no output. This is because a transformer works on the principle of elctromagnetic induction, which requires a voltage source that changes with time (alternating source). Thus since a dc supply is unidirectuional, the transformer cannot work.
Assuming the transformer is not an autotransformer:
During the application of DC there will be an output pulse. Its voltage and duration will depend on the source impedance, applied voltage and various characteristics of the transformer. Once this has settled the output will go to virtually zero (leakage current may develop a small DC voltage on the output), but the transformer will have magnetic field around it (similar to that of a DC electromagnet). When the DC is removed there will be a output “flyback” pulse with the opposite polarity. This pulse can have an extremely high voltage and may produce a decaying high frequency oscillation. The exact nature of the pulse and oscillation will depend on how quickly and cleanly the DC is interupted, and the magnetic characteristics of the transformer and other circuitry.
If it is an autotransformer:
There will still be pulses on application and removal of the DC, but there will also be a voltage on the output while the DC is