Q1: Drying of a solid involves __________ transfer.

ANS:C - both heat and mass

Drying of a solid involves both heat and mass transfer. Explanation:

• Drying is the process of removing moisture or volatile substances from a solid material to reduce its moisture content.
• Heat transfer is involved in providing the energy required to evaporate the moisture from the solid material. This heat energy increases the temperature of the solid, facilitating the conversion of liquid water into vapor.
• Mass transfer is involved in the movement of moisture molecules from the interior of the solid material to the surface, where they can evaporate into the surrounding atmosphere. This mass transfer occurs through diffusion or capillary action, depending on the properties of the solid material and the surrounding environment.
• Therefore, both heat transfer and mass transfer mechanisms are essential for the drying process to occur effectively.
• In summary, drying of a solid involves both heat and mass transfer mechanisms.