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

Discussion

The efficiency of a single-phase induction motor compared with a three-phase machine of the same rating is

  • A.identical, the two machines behaving in the same way
  • B.higher, because the rotor carries no current at all
  • C.lower, because of the backward field's losses
  • D.higher, because there is only one winding to supply

Answer: C

The backward component drives current in the rotor without contributing useful torque, and the elliptical field gives a poorer utilisation of the iron and copper. Single-phase machines are therefore confined to small ratings.

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

Post your comment

Please log in or register to post a comment.