Motor and Trafo - What's the Difference?

check if the examiner were 'intoxcated'

A trafo mostly makes significantly less rotations per minute.

OK, I give up........what the heck IS a trafo? As near as I can tell, it is the German word for transformer. I must be missing something.

I going to guess that trafo means transformer. Going with that, then friction (bearing and windage) losses are a relatively small part of the difference. There are 97% and 98% efficient motors, so friction alone is pretty small.

From here on, this is largely conjucture:

I think that the basic reason has to do with the difficulty of creating an ideal induction environment as the rotor moves. There may be one rotor position (vs pole location) in which the motor is optimally efficient, and every other rotor position is less than optimal (both inductively and mechanically), causing eddy current heating of the motor. So the 9% is mainly seen as heat.

basically in a transformer the primary and secondary are linked through magnetically .In a motor there is an air gap between the stator (Primary) and Rotor (Shorted secondary when Running in wound rotor and always in cage rotor).The major difference is due to the stampings .In transformer Cold rolled low loss stampings are used. In motors only in Energy efficient and HT motors CRGO is used .Again higher the rating higher the efficiency both in motor and Transformer. If U compare a 5HP motor eff with a40MVA transformer and conclude 9% is windage and friction loss God help.