Ashish Singh last edited by
@Siddhartha-Ghosh it's not an AC source.....
@Siddhartha-Ghosh a transformer is an AC device which works on static induced EMF. In order to induce emf there must zero be a relative motion between the conductor and the flux so that flux cutting action takes place, for this either the conductor can be moving Or the Supply can be AC. As in transformer the machine itself is stationary hence the supply should be AC. But as in question if DC supply is connected across the primary hence no emf will induce in primary and therefore no emf in secondary hence zero.