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**141. The refrigerant commonly used in automotive air conditioning systems is:**
– A. R-12
– B. R-22
– C. R-134a
– D. R-410A

**142. The primary purpose of the accumulator in a refrigeration system is to:**
– A. Store excess refrigerant during off-cycle periods
– B. Prevent liquid refrigerant from entering the compressor
– C. Increase the efficiency of the condenser
– D. Provide additional cooling capacity during peak demand

**143. The process of desuperheating in a refrigeration cycle involves:**
– A. Heating the refrigerant above its condensing temperature
– B. Cooling the refrigerant below its condensing temperature
– C. Expanding the refrigerant in the expansion valve
– D. Increasing the pressure of the refrigerant in the condenser

**144. The coefficient of performance (COP) of a refrigeration system can be improved by:**
– A. Increasing the condenser temperature
– B. Decreasing the evaporator temperature
– C. Increasing the pressure drop in the expansion valve
– D. Decreasing the size of the compressor

**145. The refrigerant commonly used in household refrigerators and air conditioners before being phased out due to environmental concerns is:**
– A. R-12
– B. R-22
– C. R-134a
– D. R-410A

**146. The process of superheating in a refrigeration cycle involves:**
– A. Heating the refrigerant above its condensing temperature
– B. Cooling the refrigerant below its condensing temperature
– C. Expanding the refrigerant in the expansion valve
– D. Increasing the pressure of the refrigerant in the condenser

**147. In a refrigeration system, the purpose of the sight glass is to:**
– A. Indicate the temperature of the refrigerant
– B. Monitor the pressure of the refrigerant
– C. Provide a visual indication of the refrigerant’s state
– D. Control the flow rate of the refrigerant

**148. The process of dehumidification in a refrigeration system occurs primarily in the:**
– A. Condenser
– B. Evaporator
– C. Compressor
– D. Expansion valve

**149. The refrigerant commonly used in modern residential air conditioning systems is:**
– A. R-12
– B. R-22
– C. R-134a
– D. R-410A

**150. The evaporator coil in a refrigeration system is typically made of:**
– A. Copper
– B. Aluminum
– C. Stainless steel
– D. Plastic