MODERN REFRIGERATION AIR CHAPTER 16 REVIEW QUESTIONS AND ANSWERS

1. The type of circuit diagram that shows the approximate physical location of components in relation to each other is a ______ diagram. a. Boolean b. Ladder c. Pictorial d. Venn 2. The type of circuit diagram that shows the components and connections arranged in the order that they activate during circuit operation is a ______ diagram. a. Boolean b. Ladder c. Pictorial d. Venn 3. Which of the following is not one of the three main components used in an HVACR control system? a. Controlled device b. Controller c. Operator d. Sensor 4. Which device responds to changes in the signals from sensors and issues signals to controlled devices? a. Relay b. Contractor c. Thermocouple d. Controller 5. In control systems, the desired condition is called the _______. a. Control point b. Cut-in c. Offset d. Set point 6. The term for the present condition in a conditioned space is the _____. a. Control point b. Cut-in c. Offset d. Set point 7. Sometimes called error, the deviation between set point and control point is the ______. a. Differential b. Cut-in c. Offset d. Range 8. The temperature or pressure value at which a device begins operation is its ______. a. Cut-in b. Cut-out c. Differential d. Range 9. The temperature or pressure value at which a device ceases operation is its _______. a. Cut-in b. Cut-out c. Differential d. Range 10. The set of numbers between and including a control system’s cut-in and cut-out values is called the system’s _____. a. Offset b. Set point c. Differential d. Range 11. A control system’s _____ is the difference between the cut-out value and the cut-in value. a. Adjustment b. Average c. Differential d. Range 12. Which of the following statements about adjustment is true? a. It increases a system’s differential b. It decreases a system’s differential c. It affects a system’s average temperature d. It has no effect on how a system operates 13. Reducing a system’s cut-out temperature without changing its cut-in temperature is an example of ______. a. Differential adjustment b. Range adjustment c. Combination control d. Actuator modulation 14. If a cooling system’s cut-in temperature I decreased, but its cut-out temperature stays the same, which of the following is true? a. The average temperature decreases b. The average temperature increases c. The system has a greater differential d. The compressor will run for longer spans of time 15. Which of the following devices is not used as a temperature sensor in thermostatic motor controls? a. Bimetal device b. Electronic sensor c. Fuse d. Sensing bulb 16. A(n) ______ element opens an electrical circuit when the temperature rises. a. Above-atmospheric-pressure b. Below-atmospheric-pressure c. Range d. Pickup 17. Sensing bulbs typically use a bellows or _______ to open and close contact points as their internal pressure changes. a. Push button b. Diaphragm c. Thermistor d. Solid-state device 18. Which type of bimetal device expands or contracts and tilts a mercury switch that serves as the electrical contact between wires? a. Bimetal disk b. Bimetal coil c. Bourdon tube d. Thermistor 19. Which type of pressure motor control regulates compressor operation to maintain a specific evaporator pressure? a. High-pressure motor control b. Low-pressure motor control c. Low-pressure safety control d. Oil pressure motor control 20. If the low-side pressure drops below a safe limit due to refrigerant loss or an evaporator freeze-up, a(n) ______ switch off the compressor motor. a. Circuit breaker b. Low-pressure safety control c. Oil pressure motor control d. Wheatstone bridge 21. Which of the following devices does not operate on electromagnetic principles?