Machine-translated by Google. Questions are authored in English.
Top

Discussion

A single-phase winding fed with alternating current produces

  • A.a steady field fixed in both magnitude and direction
  • B.a pulsating field that can be resolved into two counter-rotating fields
  • C.a field of entirely constant magnitude revolving steadily at the synchronous speed
  • D.no magnetic field at all in the air gap of the machine

Answer: B

The two components of equal magnitude produce equal and opposite torques at standstill, which is exactly why such a machine will not start by itself. Making the field elliptical with an auxiliary winding gives the necessary net torque.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.