1. The starting winding of a single-phase motor is placed in the;
(A) Rotor
(B) Stator
(C) Armature
(D) Field
2. One of the characteristics of a single-phase motor is that it;
(A) Is self-starting
(B) Is not self-starting
(C) Requires only one winding
(D) Can rotate in one direction only
3. After the starting winding of a single-phase induction motor is disconnected from supply, it continues to run only on ............winding.
(A) Rotor
(B) Compensating
(C) Field
(D) Running
4. If starting winding of a single-phase induction motor is left in the circuit, it will;
(A) Spark at light loads
(B) Run slower
(C) Run faster
(D) Draw excessive current and overheat
5. The direction of rotation of a single-phase motor can be reversed by;
(A) Reversing connections of both windings
(B) Reversing connections of starting winding
(C) Using a reversing switch
(D) Reversing supply connections
6. If a single-phase induction motor runs slower than normal, the more likely defect is;
(A) Worn bearings
(B) Shorted running winding
(C) Open starting winding
(D) Improper fuses
7. The capacitor in a capacitor-start induction-run AC motor is connected in series with ...... winding.
(A) Squirrel-cage
(B) Running
(C) Starting
(D) Compensating
8. A permanent-split single-phase capacitor motor does not have;
(A) Centrifugal switch
(B) Starting winding
(C) Squirrel-cage rotor
(D) High power factor
9. The starting torque of a capacitor-start induction-run motor is directly related to the angle α between its two winding currents by the relation;
(A) cos α
(B) sin α/2
(C) tan α
(D) sin α
10. In a two-value capacitor motor, the capacitor used for running purposes is a/an;
(A) Paper-spaced oil-filled type
(B) Dry-type AC electrolytic capacitor
(C) Air-capacitor
(D) Ceramic type
11. If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open, then;
(A) Electrolytic capacitor will, in all probability, suffer breakdown
(B) Motor will not carry the load
(C) Motor will draw excessively high current
(D) Motor will not come up to the rated speed
12. Each of the following statements regarding a shaded-pole motor is true except;
(A) Its direction of rotation is from unshaded to shaded portion of the poles
(B) It has very poor efficiency
(C) It has high starting torque
(D) It has very poor p.f.
13. Compensating winding is employed in an AC series motor in order to;
(A) Compensate for decrease in field flux
(B) Increase the total torque
(C) Reduce effects of armature reaction
(D) Reduce the sparking at brushes
14. A universal motor is one which;
(A) Is available universally
(B) Can be marketed internationally
(C) Runs at dangerously high speed on no-load
(D) Can be operated either on DC or AC supply
15. In a single-phase series motor the main purpose of inductively-wound compensating winding is to reduce the;
(A) Reactance EMF of commutation
(B) Rotational EMF of commutation
(C) Transformer EMF of commutation
(D) None of the above
16. A repulsion motor is equipped with;
(A) Neither (A) nor (B)
(B) Slip-rings
(C) A repeller
(D) A commutator
17. A repulsion-start induction-run single-phase motor runs as an induction motor only when;
(A) Brushes are shifted to neutral plane
(B) Short-circuiter is disconnected
(C) Stator winding is reversed
(D) Commutator segments are short-circuited
18. If a DC series motor is operated on AC supply, it will;
(A) Have poor efficiency
(B) Have poor power factor
(C) All of the above
(D) Spark excessively
19. An outstanding feature of a universal motor is its;
(A) Highest output kW/kg ratio
(B) Slow speed at all loads
(C) Excellent performance on DC supply
(D) Best performance at 50 Hz supply
20. Speed of the universal motor is;
(A) Dependent on frequency of supply
(B) Proportional to frequency of supply
(C) Independent of frequency of supply
(D) None of the above
21. In the shaded pole squirrel cage induction motor the flux in the shaded part always;
(A) Leads the flux in the unshaded pole segment
(B) Lags the flux in the unshaded pole segment
(C) Is in phase with the flux in the unshaded pole segment
(D) None of the above