(a)[1]
State the part of the electromagnetic spectrum from which thermal energy is radiated by the heater.
(b)[2]
Explain why the shiny metal surface behind the heating elements increases the amount of thermal energy radiated into the room.
(c)[1]
The heater’s metal outer casing is earthed. State why this is an important safety feature.
(d(i))[2]
Calculate the current in a single heating element.
(d(ii))[2]
Show that the heater’s electrical power is approximately $1200\,\text{W}$. State any equation you use in words or symbols.
(d(iii))[3]
Calculate the thermal energy emitted by the heater in (d)(ii) over $60\,\text{s}$. Give your answer to two significant figures.