DC & Induction Motor

Main difference - AC motors run on AC supply and DC motors run on DC supply. And who says AC motors are preferred? The teacher who set your homework? In many cases DC motors are widely preferred.

In many areas DC motors still used where variable speeds are required. I believe your choice comes down to cost. Controllers for DC unit are generally lower cost. But, the cost of DC motors is quite high. AC motors on the other hand are much cheaper and in some case lighter as well. Side bit the controllers can cost a bit more. I guess it depends upon the designers need and comfort zone when setting up systems.

"what are the diff b/w Ac Motor And Dc motors in detail. & why we preferred AC motor as compare to dc Motor."

Whenever I see an inappropriately demanding type of query, such as one using the words "in detail", I can tell this is a homework assignment. 30 years out of college and those words still make me bristle with fear of getting a bad grade...

thn the txt syntx, lack of punctuation, ovr use of abbrev and lack of capitaliz indicates 2 me some1 under 22YO who has yet 2 lern 2 commic8 properly

Ergo, student.

Feh... go learn how to do your own research without asking others to do it for you.

It has got something to do with AC motors not running on batteries and DC motors not running on mains either without some sort of interposing equipment.