A porous clay pot filled with water is placed in a dry, hot room. Water slowly seeps through the clay to the outer surface, keeping the outside of the pot damp. Why does this help to lower the temperature of the water inside the pot?
Water evaporates from the outer surface, so the remaining water becomes cooler.
Clay has an extremely high specific heat capacity that cools the water.
The damp outer surface insulates the inner water from the surrounding warm air.
Water seeping through clay is always colder than the surrounding air.
528 exam-style questions on CIE IGCSE Physics 2.2 Thermal properties and temperature, covering 2.2.1 Thermal expansion of solids, liquids and gases, 2.2.2a Internal energy and temperature, 2.2.2b Specific heat capacity, 2.2.3a Melting, boiling, condensation and solidification, 2.2.3b Evaporation, and 2.2.3c Cooling by evaporation. Each one has a worked solution and a mark scheme showing where the marks go.