1. In a squirrel cage motor, the rotor is constructed of steel laminations mounted rigidly on the motor shaft.
a. True
b. False
2. Locked rotor currents for different motor types vary from 10 to 20 times the full-load current of the motor.
a. True
b. False
3. Slip refers to the twisting or turning of the motor shaft.
a. True
b. False
4. By reducing the starting voltage, at the motor terminals, the starting torque is decreased.
a. True
b. False
5. With impedance starting, reactors are used in series with the motor.
a. True
b. False
Name: Class: Date:
Unit 25 The Motor and Starting Methods
6. The rotor winding consists of many copper, or ____, bars fitted into slots in the rotor.
a. nickel b. aluminum
c. zinc d. platinum
7. The slip at rated load may vary from 3 percent to ____ for different types of motors.
a. 10 percent b. 20 percent
c. 30 percent d. 40 percent
8. The most common function of reduced voltage starting devices is to ____ the starting current of an induction motor.
a. slip b. torque
c. reduce d. increase
9. With full-voltage starting: ____.
a. reactors are used in series with the motor
b. a hand-operated or automatic starting switch throws the motor directly across the line
c. a resistance unit connected in series with the stator reduces the starting current
d. the stator of the motor is star connected for starting and delta connected for running
10. With part winding starting: ____.
a. reactors are used in series with the motor
b. a resistance unit connected in series with the stator reduces the starting current
c. the stator windings of the motor are made up of two or more circuits
d. the stator of the motor is star connected for starting and delta connected for running
Name: Class: Date:
Unit 25 The Motor and Starting Methods