quiz 17 and 9 and 10 electricity hvac

1. A motor's speed is determined by ____. D) number of motor poles 2. Start windings are placed ____ with the run windings. C) slightly out of phase 3. The start windings have ____. B) more turns than the run windings 4. A split-phase has a ____ winding and a ____ winding. A) start, run 5. When a general duty split-phase motor reaches approximately 75% of its operating speed, the start winding is de-energized by a ____. C) centrifugal switch 6. A split-phase motor that has a current relay and a start capacitor is called a(n) ____ motor. B) Capacitor Start, Induction Run (CSIR) 7. When a Capacitor Start Induction Run (CSIR) motor is running and up to speed, what is the total capacitance acting on the motor? (Assume the run capacitor is 5 microfarads and the start capacitor is 20 microfarads, if present.) B) 5 microfarads 8. A permanent split capacitor (PSC) motor that is running and up to speed will have the start winding ____. A) energized 9. When a Capacitor Start, Capacitor Run (CSCR) motor initially starts, what is the total capacitance acting on the motor? (Assume the run capacitor is 5 microfarads and the start capacitor is 20 microfarads, if present.) D) 25 microfarads 10. Capacitors wired in series with the starting winding provide a(n) ____. B) greater starting torque 11. The shaded pole motor ____. A) has little starting torque 12. Three phase motors have ____. C) run windings only 13. A current magnetic relay opens and closes its contacts based on the ____. D) current in the run winding 14. The starting device usually used on single phase, fractional horsepower motors requiring low starting torque is the ____. B) current relay 15. The positive temperature coefficient resistor start device is a type of ____. B) variable resistor 16. A permanent split-capacitor motor has a ____. C) run capacitor only 17. The magnetic fields generated in the rotor and stator of a motor causes the rotor to be pushed around the shaft. B) False 18. The heavier the load on an operating motor, the greater the amount of slip. A) True 19. In order to change the direction of rotation of a split-phase motor, the technician must change the direction of current flow through the start winding. A) True 20. The centrifugal switch mounted on the shaft of a split-phase motor has a normally closed contact. A) True 21.The contact(s) in a potential type starting relay are normally closed. A) True 22. Once the start winding and the start capacitor have been removed for the circuit, the motor will continue to operate with only the run winding energized. A) True 23. The microfarad rating of the run capacitor is much lower than that of the start capacitor for any given motor application. A) True 24. A Capacitor Start Capacitor Run (CSCR) motor that is wired with a potential relay will have the start winding energized when the relay's contacts open. A) True 25. The contact(s) in a current type starting relay are normally closed. B) False 26. The resistances of the windings in a three phase motor are all equal. A) True 1. The resistance-start-induction-run motor has only a starting winding. B) False 2. The capacitor consists of two aluminum plates with an insulator between them. A) True 3. Motors are selected mainly because of the starting torque required for the motor to perform its function. A) True 4. All magnets have three poles. B) False 5. Motor speed is generally used to classify motors into different types. B) False 6. Magnetism can only be produced by the earth's core. B) False 7. To make an electric motor move continuously, the magnetic field must rotate. A) True 8. The permanent magnet is a piece of magnetic material that has been magnetized and can hold its magnetic strength for a reasonable length of time. A) True 9. An alternating current of 60 hertz changes direction 100 times per second. B) False 10. An alternating current motor's speed is determined by the frequency of the power supply only.B) False .*********************************************************************************************************************************************************************************************************************************************************** 1. The back electromotive force produced by the starting winding of a motor is not the controlling factor of a potential relay. B) False 2. The back electromotive force is the amount of voltage produced in the starting winding of a motor. A) True 3. Single-phase motors, with the exception of the permanent split-capacitor motor, must have some means of dropping the starting winding out of the circuit. A) True 4. The current relay is built much like a solenoid, with copper wire wrapped around a steel hollow core holding a steel plunger. A) True 5. The advancement of solid-state controls has produced another type of current-sensitive relay, a PTC starting switch. A) True 6. On all electric motors, the starting amperage is less than the running amperage because the rotor is stationary on startup. B) False 7. In an open-type motor, dropping the starting winding out of the circuit is accomplished by a centrifugal switch mounted on the motor that opens once the motor has reached 35% of its full speed. B) False 8. The running amperage of an electric motor is usually stated as the full-load amperage. A) True 9. The potential relay is easy to troubleshoot because only two parts of the relay must be checked. A) True

1. A motor's speed is determined by ____. D) number of motor poles 2. Start windings are placed ____ with the run windings. C) slightly out of phase 3. The start windings have ____. B) more turns than the run windings 4. A split-phase has a ____ winding and a ____ winding. A) start, run 5. When a general duty split-phase motor reaches approximately 75% of its operating speed, the start winding is de-energized by a ____. C) centrifugal switch 6. A split-phase motor that has a current relay and a start capacitor is called a(n) ____ motor. B) Capacitor Start, Induction Run (CSIR) 7. When a Capacitor Start Induction Run (CSIR) motor is running and up to speed, what is the total capacitance acting on the motor? (Assume the run capacitor is 5 microfarads and the start capacitor is 20 microfarads, if present.) B) 5 microfarads 8. A permanent split capacitor (PSC) motor that is running and up to speed will have the start winding ____. A) energized 9. When a Capacitor Start, Capacitor Run (CSCR) motor initially starts, what is the total capacitance acting on the motor? (Assume the run capacitor is 5 microfarads and the start capacitor is 20 microfarads, if present.) D) 25 microfarads 10. Capacitors wired in series with the starting winding provide a(n) ____. B) greater starting torque 11. The shaded pole motor ____. A) has little starting torque 12. Three phase motors have ____. C) run windings only 13. A current magnetic relay opens and closes its contacts based on the ____. D) current in the run winding 14. The starting device usually used on single phase, fractional horsepower motors requiring low starting torque is the ____. B) current relay 15. The positive temperature coefficient resistor start device is a type of ____. B) variable resistor 16. A permanent split-capacitor motor has a ____. C) run capacitor only 17. The magnetic fields generated in the rotor and stator of a motor causes the rotor to be pushed around the shaft. B) False 18. The heavier the load on an operating motor, the greater the amount of slip. A) True 19. In order to change the direction of rotation of a split-phase motor, the technician must change the direction of current flow through the start winding. A) True 20. The centrifugal switch mounted on the shaft of a split-phase motor has a normally closed contact. A) True 21.The contact(s) in a potential type starting relay are normally closed. A) True 22. Once the start winding and the start capacitor have been removed for the circuit, the motor will continue to operate with only the run winding energized. A) True 23. The microfarad rating of the run capacitor is much lower than that of the start capacitor for any given motor application. A) True 24. A Capacitor Start Capacitor Run (CSCR) motor that is wired with a potential relay will have the start winding energized when the relay's contacts open. A) True 25. The contact(s) in a current type starting relay are normally closed. B) False 26. The resistances of the windings in a three phase motor are all equal. A) True 1. The resistance-start-induction-run motor has only a starting winding. B) False 2. The capacitor consists of two aluminum plates with an insulator between them. A) True 3. Motors are selected mainly because of the starting torque required for the motor to perform its function. A) True 4. All magnets have three poles. B) False 5. Motor speed is generally used to classify motors into different types. B) False 6. Magnetism can only be produced by the earth's core. B) False 7. To make an electric motor move continuously, the magnetic field must rotate. A) True 8. The permanent magnet is a piece of magnetic material that has been magnetized and can hold its magnetic strength for a reasonable length of time. A) True 9. An alternating current of 60 hertz changes direction 100 times per second. B) False 10. An alternating current motor's speed is determined by the frequency of the power supply only.B) False .*********************************************************************************************************************************************************************************************************************************************************** 1. The back electromotive force produced by the starting winding of a motor is not the controlling factor of a potential relay. B) False 2. The back electromotive force is the amount of voltage produced in the starting winding of a motor. A) True 3. Single-phase motors, with the exception of the permanent split-capacitor motor, must have some means of dropping the starting winding out of the circuit. A) True 4. The current relay is built much like a solenoid, with copper wire wrapped around a steel hollow core holding a steel plunger. A) True 5. The advancement of solid-state controls has produced another type of current-sensitive relay, a PTC starting switch. A) True 6. On all electric motors, the starting amperage is less than the running amperage because the rotor is stationary on startup. B) False 7. In an open-type motor, dropping the starting winding out of the circuit is accomplished by a centrifugal switch mounted on the motor that opens once the motor has reached 35% of its full speed. B) False 8. The running amperage of an electric motor is usually stated as the full-load amperage. A) True 9. The potential relay is easy to troubleshoot because only two parts of the relay must be checked. A) True