Final answer:
The refrigerant that enters the expansion or throttling device is in a liquid state and undergoes expansion, which leads to a decrease in temperature necessary for the cooling process in a refrigerator.
Step-by-step explanation:
The refrigerant that enters the expansion or throttling device, also known as the metering device, is in a liquid state. As it passes through this device, the pressure of the refrigerant decreases, causing it to rapidly expand. This expansion leads to a decrease in temperature, which is essential for the cooling process in the refrigerator.
For example, in a household refrigerator, the refrigerant enters the expansion valve as a high-pressure liquid and exits as a low-pressure liquid. This low-pressure liquid then enters the evaporator coils, absorbing heat from the refrigerator, and evaporates into a gas. This gas is then compressed by the compressor, raising its temperature and pressure before entering the condenser coils to release heat to the surroundings.