This question is about three different methods used to heat solid agar gel spheres in a laboratory.
On a traditional laboratory hotplate, a solid agar gel sphere is placed in a metal beaker filled with water, which sits directly on top of the solid heating plate.
Describe how thermal energy is transferred from the hotplate to heat up the entire interior of the agar gel sphere.
A laboratory microwave oven is used to heat an identical agar gel sphere submerged in water within a glass beaker.
Explain how energy is transferred to heat up the entire agar gel sphere, and discuss whether the common claim that microwaves 'heat substances from the inside out' is correct.
In an electromagnetic induction heater, an induction coil is positioned directly below the ceramic support plate of the workspace.
A steel beaker containing water and a submerged agar gel sphere is placed on the plate. An alternating current is switched on in the coil under the plate. The coil itself does not directly heat the ceramic plate.
Describe how energy is transferred to heat up the entire agar gel sphere.
