Show More Ask Question

1 Answer

Answer :

The speed control of universal motor used for sewing machines is by varying the resistance.

Like 0 like
Next Page →

Related

Answer : Speed control of a universal motor is achieved by varying field flux with tapped field windings, connecting rheostat in series, applying variable voltage by means of silicon controlled rectifier, applying variable voltage by means of variable auto-transformer.

Answer : The speed of a universal motor is usually reduced by using gearing.

Answer : The speed/load characteristics of a universal motor is same as that of D.C. series motor.

Answer : The speed of a universal motor is generally reduced by using gear trains.

Description : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above

Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases