This question is about an electric cooker, which consists of an oven and an electromagnetic induction hob.
The volume of the oven is 0.065 m3. The air inside the oven behaves as an ideal gas.
The temperature of the oven increases from room temperature to 200 °C.
Show that the internal energy of the air in the oven is the same at all temperatures of the oven. Support your answer with an explanation of the motion of the air molecules in terms of kinetic theory.
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Fig. 4.1
Each cooking area has a coil below the glass-ceramic cover. When switched on, the coils carry a high-frequency alternating current.
A metal saucepan is placed above one of the coils. A large alternating current is induced in
the saucepan base, and this causes the saucepan to heat up.
Fig. 4.2
On Fig. 4.2, sketch the magnetic field pattern for the current-carrying coil.
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Fig. 4.3
Explain the origin of this large current.
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