21.   Two technicians are discussing heat transfer in an automotive A/C system. Technician A says as refrigerant converts from a gas to a liquid as it receives heat. Technician B says an expansion valve drops refrigerant pressure before it enters the evaporator. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or

26.    Technician A says a frozen point on an A/C component or connection indicates a restriction in the system. Technician B says a frozen expansion valve will cause a low - low side pressure. Who is correct?

A. Technician A

B. Technician B

C. Both Technicians A and B

D. Neither Technician A or B

22.   Technician A says a open A/C relay winding can prevent A/C clutch engagement. Technician B says a loose serpentine belt can prevent clutch engagement. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

27.   Technician A says an ambient temperature sensor senses the outside air temperature. Technician B says this sensor is a variable resister used by the automatic control system. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

23.   A vehicle has a high - high side pressure. All of these can cause this condition except:

A. a restricted condenser.

B. no fan operation.

C. an over tightened A/C belt.

D.an overcharged system.

28.   All of these are true about A/C receiver drier except it:

A. is a liquid tank.

B. is debris a filter.

C. is located on the low side.

D. absorbs moisture.

24.    Technician A says mineral oil is used to lubricate 134a A/C systems. Technician B says A/C oil mixes with the refrigerant to lubricate the compressor, seals, o-rings etc. in the A/C system. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

29.   R 134a Refrigerant:

A. changes from a vapor to a liquid as it absorbs heat.

B. systems have less refrigerant capacity than similar R12 systems.

C. has a very high boiling point.

D. is a CFC that contains chlorine.

25.   Two technicians are discussing the cycling clutch system. Technician A says the temperature cycling clutch switch uses a bulb placed on the inlet port of the evaporator core. Technician B says a typical pressure cycling switch is located on the accumulator or the low side of a system. Who is Correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

30.  Two technicians are discussing electric cooling fans and A/C performance. Technician A says electric fans regulate refrigerant temperatures more precisely than belt driven fans do. Technician B says they may are controlled by temperature and pressure actuated switches. Who is correct?

A. Technician A

B. Technician B

C. Both Technicians A and B

D. Neither Technician A or B