Transformer and Its working

Transformer does not work on:

A transformer cannot work on DC. Why?

A transformer cannot work on D.C. Why?

Draw a schematic diagram of a step-up transformer . Explain its working principle . Deduce the expression for the secondary to primary voltage in terms of the number of turns in the two coils . In an ideal transformer , how is this ratio related to the currents in the two coils ?

Transformer works on