Two identical thermometers, T1 T_1\,T1 and T2T_2T2, initially show the same room temperature reading. The bulb of thermometer T2 T_2\,T2 is wrapped in a piece of cotton soaked in water at room temperature, while the bulb of T1 T_1\,T1 is left dry. A fan is turned on to blow air at room temperature over both thermometers.
Which of the following statements correctly compares their readings and explains the underlying physical process?
T1T_1T1 shows a higher temperature than T2T_2T2 because the blowing air transfers thermal energy to T1T_1T1.
T1T_1T1 shows a higher temperature than T2T_2T2 because water evaporates from the wet cotton, absorbing latent heat and cooling T2T_2T2.
T2T_2T2 shows a higher temperature than T1T_1T1 because the wet cotton acts as an insulator, trapping heat in T2T_2T2.
T2T_2T2 shows a higher temperature than T1T_1T1 because the evaporation of water is an exothermic process that warms T2T_2T2.
313 exam-style questions on CIE IGCSE Physics 2.2.3a Melting, boiling, condensation and solidification. Each one has a worked solution and a mark scheme showing where the marks go.