An industrial food warmer uses two different methods to keep metal dishes hot:
Method 1: A solid metal heating plate is clamped directly against the bottom of a metal dish, leaving no air gap.
Method 2: A halogen lamp underneath a glass top glows brightly to heat the bottom of a metal dish placed on the glass top.
Which statement is correct?
In Method 1, energy is transferred to the metal dish primarily by convection.
In Method 2, energy is transferred through the glass top to the dish by convection.
In Method 1, energy is transferred to the metal dish by conduction.
In Method 2, the halogen lamp transfers less energy by radiation than the metal heating plate in Method 1.
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.