Page 751 - Basic Electrical Engineering

c. develop a pulsating torque
d. not develop any torque at all.

7. A dc series motor will work satisfactory on ac supplying provided

a. the yoke and the poles are completely laminated
b. only the poles are laminated
c. the air gap is reduced
d. compensating poles are introduced.

8. The ceiling fan in your home has a

a. shaded pole-type motor
b. dc series motor
c. universal motor
d. capacitor-start motor.

9. In a capacitor start induction motor, the capacitor is connected

a. in series with the main winding
b. in series with the auxiliary winding
c. across the supply terminals
d. in parallel with the auxiliary winding.

10. The rotor of a stepper motor

a. has no winding
b. has no commutator
c. has no slip rings
d. all these as in (a), (b), and (c).

11. According to double revolving field theory, an alternating field can be considered equivalent
to

a. two revolving fields of constant magnitude rotating at synchronous speed in the same
direction
b. two revolving fields of constant magnitude rotating at synchronous speed but in
opposite directions
c. two revolving fields of variable magnitude rotating at synchronous speed but in
opposite directions
d. two revolving fields of variable magnitude rotating at synchronous speed in the same
direction.

12. A universal motor is

a. a series motor designed to operate on ac
b. a series motor designed to operate on both ac and dc
c. a series motor designed to operate on dc