induced current

why induced current is always ac but not in dc form??

plz answer it if any bidy can explain,i wl b thankful

It is due to the law of inductance: V = L di/dt which says if there is no change in current over time than the induced Voltage will be zero. So DC will not induce anything and will not see any DC Voltage from inductance.
Also have a look on WIKI.

Because a current is only induced in a conductor by a changing magnetic field. Only a changing current can produce a changing magnetic field (in stationary conductors). Now, technically, a DC current _can_ create a changing magnetic field if that DC current is changing in _magnitude_ but not _polarity_--e.g. from a positive current to a more, or less, positive current OR from a negative current to a more, or less, negative current (if you consider "AC" to mean a current that "Alternates" between positive and negative).

http://en.wikipedia.org/wiki/Lenz's_law

Wow, even if we did explain can you read?

Wow Earl can you feel empathy?
Even if it is a beginner question it is NOT a stupid question.
Would you have liked that answer when you were learning electronics?

Earl, I'm not quite sure what ur objecting to -- the use of abbrevs?

It is a legitimate question.

THNX sir. i got it now.

Thanks for supporting the question