The mechanical displacement of the rotor with respect to the stator, in polyphase multipolar synchronous motors running at full load, is of the order of

The correct answer is B. two degrees.

A synchronous motor is an AC electric motor that runs at a constant speed synchronized with the AC power supply. The rotor of a synchronous motor is magnetically locked to the stator field, and the two rotate at the same speed. The mechanical displacement of the rotor with respect to the stator is therefore very small, typically on the order of two degrees.

Option A is incorrect because the rotor is not perfectly aligned with the stator field. Option C is incorrect because the mechanical displacement is typically much smaller than five degrees. Option D is incorrect because the mechanical displacement is typically much smaller than ten degrees.