A microwave oven heats food containing water | vedclass

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Question

(A) Microwave ovens operate at a frequency of $2.45\,GHz$. This is $NOT$ the resonant frequency of a water molecule. If $2.45\,GHz$ were the resonant

Vedclass · Accepted Answer

The frequency of microwaves has no relation to the natural frequency of water molecules.

Vedclass · Answer

(A) Microwave ovens operate at a frequency of $2.45\,GHz$. This is $NOT$ the resonant frequency of a water molecule. If $2.45\,GHz$ were the resonant frequency of water molecules, the microwaves would all be absorbed in the surface layer of the food, and the interior would not be cooked. Therefore, the efficiency of heating is not due to resonance, but rather the rotation of polar water molecules in the oscillating electric field of the microwaves. Since none of the provided options correctly describe the physical mechanism, and the question asks for the condition, it is important to note that the premise of resonance is a common misconception. However, in the context of standard physics curriculum questions, option $A$ is the most scientifically accurate statement regarding the relationship between the frequencies.

$A$ microwave oven heats food containing water molecules very efficiently under which of the following conditions?

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