Question

can a transformer work on d.c

Answer 1

For a transformer to work, the current in one coil has to somehow make current flow in the other coil and the circuit it's connected to. A DC current in one coil will make a magnetic field on the other coil, but a magnetic field by itself won't drive any electrons around.

Answer 2

yes because there are 2 types of transformers one ac and the other dc