Due to which of the following processes the water remains cold in the pitcher?

The process responsible for keeping the water cold in the pitcher is evaporation. Evaporation is the phase transition from liquid to gas that occurs at the surface of the water, where molecules gain enough energy to escape into the air. As water molecules evaporate, they take away heat energy from the remaining water, thereby cooling it down.

This cooling effect is due to the principle of latent heat, where energy is absorbed or released during a phase transition without a change in temperature. In this case, the absorbed heat energy is used to break the intermolecular bonds between water molecules, allowing them to escape into the air as vapor. The remaining water loses heat energy, resulting in a decrease in temperature and the sensation of coldness. Therefore, the correct answer is [B] Evaporation.