An electric convection heater is used to warm the air in a study.
State the main process by which thermal energy is transferred through the air in the room.
Explain, in terms of air density changes, how the entire room is warmed by this heater.
The power of the heater is 1.1 kW1.1\text{ kW}1.1 kW when it is connected to a mains supply of 230 V230\text{ V}230 V.
Show that the normal operating current in the heater is approximately 4.8 A4.8\text{ A}4.8 A.
The plug for this heater must be fitted with a fuse. The available fuse ratings are 2 A2\text{ A}2 A, 3 A3\text{ A}3 A, 5 A5\text{ A}5 A, and 13 A13\text{ A}13 A. State which fuse rating should be selected and explain your choice.
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.