A thermometer bulb is covered by a piece of cloth soaked in alcohol. Air at room temperature is blown across the cloth.
What happens to the thermometer reading, and what is the reason for this change?
It remains constant, because the air and the alcohol are already at room temperature.
It rises, because the friction from the moving air generates thermal energy.
It falls, because conduction from the moving air lowers the temperature of the bulb.
It falls, because evaporation of the alcohol removes thermal energy from the bulb.
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.