Final answer:
The b) inside diameter of the capillary tube determines how much the pressure drops between the condenser and the evaporator, due to capillary action.
Step-by-step explanation:
The option b) inside diameter of the capillary tube determines how much the pressure drops between the condenser and the evaporator.
In physics, capillary action is the ability of a liquid to flow in narrow spaces without the assistance of external forces. This phenomenon is heavily dependent on the interaction between the cohesive forces of the liquid and the adhesive forces between the liquid and the tube's material. Capillary action is also influenced by the size of the capillary tube, specifically its radius or inside diameter. A smaller diameter results in a greater capillary rise due to the stronger adhesive forces relative to the liquid's cohesive forces. Therefore, the smaller the inside diameter of the capillary tube, the greater the height the liquid can reach, and the greater the potential for a pressure drop in a refrigeration or HVAC system as it restricts the flow of the refrigerant.