Answer :
An adiabatic capillary tube is used to reduce the pressure of the refrigerant from the condenser level to the evaporator level in refrigeration systems. So the correct option is (1) liquid.
In this process, the refrigerant typically undergoes a phase change. When the refrigerant enters the capillary tube, it is usually in a liquid state because it is coming from the condenser, where it has condensed from its gaseous state. Therefore, the correct answer is liquid.
Adiabatic means that there is no heat exchange between the refrigerant and its surroundings during the process. The capillary tube is a small, narrow tube with a small diameter. It serves as a restriction in the refrigeration system, causing a significant pressure drop as the refrigerant flows through it.
The refrigerant typically undergoes a phase change as it passes through the capillary tube. In most refrigeration systems, the refrigerant exits the condenser as a high-pressure liquid. As it enters the capillary tube, the pressure drops significantly, causing some of the liquid refrigerant to vaporize. This vaporization process absorbs heat, further lowering the temperature of the remaining liquid refrigerant. So the correct option is (1) liquid.
