DC current is flowing in the primary coil of a transformer.
<em>Choice-D</em> is the one that does NOT happen.
A. There is a magnetic field in the primary.
Yes, just as there is around EVERY current-carrying conductor.
B. Current flows in the primary.
Yes. The first sentence says so.
C. The primary gets warm.
Yes. Just like ANY current-carrying conductor that has any resistance.
<em>D. </em> Current flows in the secondary
<em>NO.</em> Current in the secondary is the result of CHANGES in the primary current. Since the primary current is DC, there aren't any changes.
A long time ago, in engineering school in a galaxy far away, I learned that when you put DC into a transformer, what comes out is smoke.
