An air conditioning unit is mounted high up on a wall near the ceiling of a room. Why is the air conditioning unit placed near the ceiling to cool the room?
Cold air sinks and warm air is displaced upwards.
Cold air is a bad conductor so heat is not conducted into the room.
Cold air is a good conductor so heat is conducted out of the room.
Cold air remains at the top and so prevents convection.
73 exam-style questions on CIE IGCSE Physics 2.3.2 Convection. Each one has a worked solution and a mark scheme showing where the marks go.