An office room is warmed using a heater to keep it comfortable during winter. Where should the heater be placed to warm all the air in the room as effectively as possible?
near the ceiling of the room
near the floor of the room
halfway up on one of the side walls
on the outside of the window
301 exam-style questions on CIE IGCSE Physics 2.3 Transfer of thermal energy, covering 2.3.1a Thermal conductors and thermal insulators, 2.3.1b Explaining thermal conduction, 2.3.2 Convection, 2.3.3a Thermal radiation, 2.3.3b Surface colour and texture, 2.3.3c Rate of emission and absorption of radiation, and 2.3.4 Consequences of thermal energy transfer. Each one has a worked solution and a mark scheme showing where the marks go.