A student investigates the heating of a metal cylinder, Y, using a constant-power electrical heater.

Explain why the temperature of cylinder Y eventually reaches a constant value, even though the heater remains switched on.
Practise Edexcel GCSE Physics Thermal radiation and energy balance with exam-style questions for Foundation and Higher tier. 46 questions, matched to the Edexcel GCSE Physics (1PH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.