$ Chapter 1

1. The _________ is the basic building block of the universe.

2. The 3 principal parts of an atom are the ________, the ________ and the ________.

3. The Proton has a ________ charge.

4. The Electron has a ________ charge.

5. The Neutron has ________ charge.

6. The proton and the neutron combine to form the ________ of an atom.

7. An electron is ________ times larger than a proton.

8. The proton weighs about ________ times more than an electron.

9. The proton is MUCH more massive than the electron. (T or F)

10. The Law of Charges states that ________ charges attract and ________ charges repel.

11. The Law of Centrifugal Force states that _______________________________.

12. The first shell of an atom can have a maximum of ________ electrons.

13. The second shell of an atom can have a maximum of ________ electrons.

14. The third shell of an atom can have a maximum of ________ electrons.

15. The fourth shell of an atom can have a maximum of ________ electrons.

16. The formula for the number of electrons in a shell is __________________ (where N=shell).

17. The outer shell of an atom is the ________ shell.

18. Any electrons in the valence shell are known as ________ electrons.

19. The Valence Shell of an atom cannot hold more than ________ electrons.

20. A Conductor has how many electrons in its Valence Shell ?

21. Which is the best conductor of Silver, Copper and Aluminum?

22. Why is copper the most common conductor?

23. Which is the best insulator of Silver, Copper and Aluminum?

24. Electricity can be defined as ____________________________________.

25. Insulators have ____________ valence electrons.

26. Centrifugal force is proportional to __________ and _________.

27. What are the 3 subatomic parts of atoms and what charge does each carry?

28. How many times larger is an electron that a proton?

29. The weight of a proton is how many times heavier than an electron?

30. State the Law of Charges

31. What force keep the electron from falling into the nucleus of an electon?

32. Materials that make the best conductors have how many valence electrons?

33. Materials that make the best conductors have how many valence electrons?

34. Electricity may be defined as ________________________________.

$ Chapter 2

1. What is a Coulomb?

2. Define the term AMPERE (AMP).

3. Define the term VOLTAGE.

4. Define the term OHM.

5. Define the term WATT.

6. An electric heating element has a resistance of 16 ohms and is connected to a voltage of 120 volts. How much current (amps) will flow in the circuit?

7. How many watts of heat are being produced by a heating element with R=16 ohms and E=120 volts?

8. A 240-volt circuit has a current flow of 20 amps. What is R ?

9. An electric motor has an apparent resistance of 15 ohms. If a current of 8A is flowing through the motro, what is the connected voltage?

10. E=240, R=8, what is I?

11. E=240, R=8, what is W?

12. W=5000, E=240, what is I?

13. W=5000, E=120, what is I?

14. Is it less expensive to use 240V for heating rather than 120V? Explain.

$ Chapter 3

1. What type of meter has a high resistance connected in series with the meter movement?

2. How is a voltmeter connected into the circuit?

3. If a voltmeter has a resistance of 5000 ohms per volt, what is the resistance of the meter when it is set on the 300-volt range?

4. What is the advantage of using a voltmeter that has a high impedance as opposed to a low-impedance meter?

5. What is an analog meter?

6. Why must an ammeter be connected in series with the load?

7. What device is used to change the scale values of an AC ammeter?

8. What is meant by the term "inline" ammeter?

9. A clamp-on ammeter has three turns of wire wrapped around the movable jaw. If the meter is indicating a current of 15 amps, how much current is actually flowing in the circuit?

10. List the three steps for reading a meter.

11. What type of meter contains its own internal power supply?

12. What precaution must be taken when using an ohmmeter?

$ Chapter 4

1. List the three types of electrical circuits.

2. What is the major characteristic of the series circuit?

3. List the three basic rules for series circuits.

4. What is the major characteristic of a parallel circuit?

5. List the three basic rules for the parallel circuit.

6. What type of circuit is used most often in industry and the home?

7. What type of circuit is used the least in industry and the home?

8. Three resistors valued at 300 ohms, 200 ohms, and 600 ohms are connected in series. What is their total resistance?

9. Three resistors valued at 300 ohms, 200 ohms, and 600 ohms are connected in parallel. What is their total resistance?

10. How are fuses and circuit breakers connected in a circuit and why are they connected this way?

$ Chapter 5

1. What is an alternator?

2. What controls the output voltage of an alternator?

3. What controls the frequency of the alternator?

4. How many degrees out of phase with each other are the voltages of a three-phase system?

5. What are the two major types of three-phase connections?

6. List the rules concerning line and phase values of current and voltage in a wye connection.

7. List the rules concerning line and phase values of current and voltage in a delta connection.

8. In a high-leg delta-connected system, what is the voltage between the high leg and neutral?

9. What type of three-phase transformer connection uses only two transformers?

10. How many degrees out of phase are the voltages of a single-phase system?

11. A two-conductor romex cable contains three wires. Which wire is not counted and why?

12. What type of circuit breaker is used to make a 240-volt connection?

13. Where does the grounding conductor connect in a panel?

14. In what two electrical units are fuses rated?

15. It has been calculated that a 290-amp fuse is needed to protect the circuit supplying an air-conditioning compressor. What standard rating of fuse should be used?

16. It has been calculated that a 290-amp fuse is needed to protect the circuit supplying an air-conditioning compressor. What size fuse disconnect will be used for the fuse?

17. What is a dual-element fuse?

$ Chapter 6

1. Name four factors that determine the resistance of wire,

2. A wire has a diameter of .057 inches. What is its circular mil area?

3. What is a mil-foot of wire?

4. When the temperature of wire increases, does its resistance increase or decrease?

5. What determines the voltage rating of wire?

6. What two factors determine the amount of voltage rating a certain type of insulation will have?

7. How much resistance does 75 feet of #24 AWG wire have?

8. If a current of 4 amps flows through the wire in question #7, how much voltage will be dropped by the wire?

$ Chapter 7

1. Name the three basic types of alternating-current loads.

2. What type of load always has its voltage and current in phase with each other?

3. In a pure-inductive circuit, how many degrees out of phase is the current with the voltage?

4. Does the current lead or lag the voltage in question #3?

5. What electrical value is used to measure inductance?

6. What is inductive reactance?

7. What electrical value is used to measure the total opposition to current flow in an AC circuit?

8. What is power factor?

$ Chapter 8

1. What three factors determine the capacitance of a capacitor?

2. What is the dielectric?

3. In what type of field is the energy of a capacitor stored?

4. In a pure-capacitive circuit, how many degrees are the current. and voltage out of phase with each other?

5. Does a capacitive current lead the voltage or lag the voltage?

6. What limits the current in a capacitive circuit?

7. Name two common types of capacitors used in the air-conditioning field.

8. What type of capacitor is generally used as the running capacitor on many air-conditioning compressors?

9. What is the advantage of an AC electrolytic capacitor?

10. What is the disadvantage of an AC electrolytic capacitor?

$ Chapter 9

1. What is a split-phase motor?

2. What are the three basic types of split-phase motors?

3. Explain the difference in construction of run windings and start windings.

4. How many degrees out of phase should be current in the start winding with the current in the run winding to develop maximum starting torque?

5. What type of capacitor is generally used with a capacitor start induction-run motor?

6. Can the micro-farad value of this capacitor be increased to improve starting torque?

7. What type of capacitor is used with a permanent-split capacitor motor?

8. Does the capacitor of a capacitor start induction-run motor help correct power factor?

9. If necessary, can an AC electrolytic capacitor of higher voltage rating be used as the starting capacitor?

10. What is a centrifugal switch used for?

$ Chapter 10

1. What is a shading coil?

2. What determines the synchronous speed of a shaded-pole motor?

3. In general, how is the direction of a shaded-pole induction motor reversed?

4. What type of rotor does the shaded-pole motor contain?

5. Name two advantages of the shaded-pole motor over the split-phase induction motor.

$ Chapter 11

1. Name two ways of changing the speed of a rotating magnetic field.

2. How does the consequent pole motor change speed?

3. Name a disadvantage of the consequent pole motor.

4. Name an advantage of a consequent pole motor.

5. How many steps of speed are common to a multi-speed fan motor?

6. Refer to figure 11-3. Explain what would happen to motor operation if the winding between low and medium should become open.

7. What is an advantage of the multi-speed fan motor over the consequent pole motor?

8. What is a disadvantage of the multi-speed fan motor when compared to the consequent pole motor?

9. How much wire resistance is common for the run winding of most split-phase motors?

10. How much wire resistance is common for the multi-speed fan motor?

$ Chapter 12

1. What are the three basic types of three-phase motors?

2. Name three factors that produce a rotating magnetic field.

3. What is synchronous speed?

4. What two factors determine the synchronous speed of a three-phase motor?

5. How is the direction of rotation of a three-phase motor changed?

6. What is the synchronous speed of a four-pole motor when connected to a 60-Hz line?

7. A dual-voltage three-phase motor has a current draw of 50 amps when connected to a 240-volt line. How much current will flow if the motor is connected for operation on 480 volts?

8. If the stator windings of a three-phase motor are connected for operation on high voltage, will the windings be connected in series or parallel?

9. If a dual-voltage motor is connected for operation on low voltage, and the motor is then connected to high voltage, will the motor operate at a faster speed?

10. Why does a dual-voltage motor draw less current when connected to low voltage than it does when connected to high voltage?

$ Chapter 13

1. What three factors determine the amount of torque produced by an AC induction motor?

2. Why does an AC induction motor draw more current when starting than it does when running?

3. Why does the current flow to the motor increase when load is added to the motor?

4. What does the code letter found on the nameplate of the motor indicate?

5. At what degree angle between the stator current and the rotor current is the maximum torque developed?

6. What type of squirrel cage rotor has the highest starting torque?

7. What type of squirrel cage rotor has the best speed regulation?

8. Why can an induction motor never operate at synchronous speed?

9. What does the locked rotor current of a motor indicate?

10. The nameplate of a squirrel cage motor indicates that the motor has a full-load speed of 875 RPM. How many poles per phase does the motor have?

$ Chapter 14

1. How many slip rings are located on the shaft of the rotor of a wound rotor induction motor?

2. What is the purpose of the slip rings?

3. Name two advantages of the wound rotor motor over the squirrel cage motor.

4. What two factors determine the amount of current flow in the rotor of a wound rotor motor?

5. What does the dashed line drawn between the three resistors shown in figure 14-2 indicate?

6. Why is the starting torque of a wound rotor induction motor higher than the starting torque of a squirrel cage induction motor?

7. The stator of a wound rotor motor has a synchronous speed of 1200 RPM when connected to a 60-Hz line. How many poles per phase are there in the rotor? 8. Refer to figure 14-5. Describe what would happen in this circuit if coil "SI" should be open when the motor started.

9. Refer to figure 14-5. Describe what would happen in this circuit if coil "TR2" should be open when the motor is started.

10. Refer to figure 14-5. Describe what would happen in this circuit if holding contact "M" should become stuck together when the motor is started and not open.

$ Chapter 15

1. Name three characteristics of a synchronous motor that the squirrel cage induction motor and the wound rotor motor do not have.

2. What is an amortisseur winding?

3. How many slip rings are located on the shaft of a synchronous motor?

4. How many slip rings are located on the shaft of a wound rotor induction motor?

5. Is a synchronous motor started with DC excitation voltage applied to the rotor?

6. What is the field discharge resistor used for?

7. A synchronous motor has an eight-pole stator. What will be the speed of the rotor when it is under full load?

8. How is it possible to know when a synchronous motor has normal excitation applied to its rotor?

9. How can a synchronous motor be made to have a leading power factor?

10. What is a synchronous condenser?

$ Chapter 16

1. What are the two basic types of industrial overload units?

2. What is the advantage of the bimetal type of industrial overload unit?

3. Industrial overload units are divided into two sections. What are they?

4. At what percentage of full-load motor current are overload units generally set to trip?

5. When using an industrial type of overload unit, what are the contacts connected in series with?

6. What is the difference between the two types of small overload units'?

7. In the small overload unit which does not contain a heater, what is used to sense the current flow through the motor?

$ Chapter 17

1. What is a solenoid?

2. What type of relays contain a shading coil?

3. What purpose does the shading coil serve?

4. What is the movable part of a relay called?

5. Why is the core material of a relay laminated?

6. What are eddy currents?

7. What effect do eddy currents have on a relay?

8. Why are contact surfaces curved?

9. What is the difference between a relay and a contactor?

10. What is the difference between a contactor and a motor starter?

$ Chapter 18

1. What electronic component is used to control the output of a solid-state relay used to control a DC voltage?

2. What electronic component is used to control the output of a solid-state relay used to control an AC voltage?

3. Explain opto-isolation.

4. Explain magnetic isolation.

5. What is meant by zero switching?

$ Chapter 19

1. What is an isolation transformer?

2. Define a step-up transformer.

3. Define a step-down transformer.

4. The primary of a transformer is connected to 120 volts AC. The secondary has a voltage of 30 volts and is connected to a resistance of 5 ohms. How much current will flow in the primary of the transformer?

5. What is the amount of Control voltage used in most residential air-conditioning systems?

6. What is the amount of control voltage used in most industrial air-conditioning systems?

7. What is the color of the primary leads of most control transformers used for residential service?

8. How many primary windings are generally contained in an industrial control transformer?

9. What is the turns ratio of each of these primary windings as compared to the secondary winding?

10. When an industrial control transformer is to be operated on 480 volts, are the primary windings connected in parallel or series?

$ Chapter 20

1. What are the four types of starting relays?

2. On what type of motor is it necessary to use a starting relay'?

3. What principle is used to operate the hot-wire relay?

4. What principle is used to operate the current relay'?

5. What type of starting relay does not sense motor current to operate?

6. What type of starting relay can be used for overload protection for the motor?

7. What type of motor can the potential relay be used with'?

8. Is the start contact of a hot-wire relay open or closed when power is first applied to the motor'?

9. Is the start contact of a current relay open or closed when power is first applied to the motor'?

10. Refer to the circuit shown in figure 20-4. What would happen if the coil of the current relay were open when the thermostat connected power to the motor circuit?

$ Chapter 21

1. What two types of small AC motors are used with variable-voltage speed control?

2. Why are these two types of motors used?

3. Name two methods of variable-voltage control for small AC motors.

4. What solid-state device is used to control the voltage applied to the motor?

5. Why is it necessary to use only controllers designed for use with inductive loads?

6. Name a method other than variable voltage used to control the speed of small AC motors.

$ Chapter 22

1. What type of motor is used to operate the timer?

2. Why is one of the motor leads brought outside the timer?

3. Name two ways of connecting the defrost timer.

4. What function does the defrost heater perform?

5. To which terminal is the pigtail lead of the timer motor connected if the timer is to operate continuously?

$ Chapter 23

1. What is a thermostat?

2. What is the advantage of an open-contact thermostat?

3. What is the disadvantage of an open-contact thermostat?

4. What is the advantage of a mercury thermostat?

5. What is used to provide a snap action for the contacts in an open-contact type of thermostat?

6. What is used to provide a snap action for the mercury thermostat?

7. What method of sensing temperature is often used with line voltage thermostats?

8. What is a programmable thermostat?

9. What is the advantage of the programmable thermostat?

10. What is a differential thermostat?

11. What are differential thermostats generally used to control?

12. What is antifreeze protection in reference to a differential thermostat?

13. What is the advantage of a low-voltage thermostat over a line voltage thermostat?