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Say, we have an alternating current source of max voltage V, and frequency v= 1 GHz connected to 2 plates as in a capacitor with an air gap of distance d, thus we get an oscillating electric field E, inside the capacitor plates, Emax = Vmax/d;, if atomised water is sprayed in between the capacitor plates the water molecules being permanent electric dipole experiences a force and torque in an non uniform oscillating electric field and thereby loses its energy in the form of heat to the surroundings. is this true?

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I think you are rediscovering the microwave oven. Microwave ovens operate by rotating water molecules similar to your layout. However, we are talking about water molecules and you must rely on quantum mechanics (i.e. think photons and rotations are quanties).

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Correct. The microwave oven works in a similar manner. Although the explanation is bit more precise when put in this way -

Since water molecules are polar in nature, they have a dipole moment; and they align themselves with the electric (electromagnetic, to be precise) field. If the field is oscillating, the molecules start rotating also. As the field reverses, the molecules also change direction. These molecules collide with each other, distributing energy throughout. This energy appears in the form of heat.

This is known as dipole rotation, and is used to raise the temperature of an object. This is the principle behind dielectric heating, which is used in microwave ovens.

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  • $\begingroup$ yeeah correct. if that is the case, how much is the amount of heat dissipated due to collision and what is the amount of heat dissipated $\endgroup$ – Pradeep G Jun 21 '17 at 11:39
  • $\begingroup$ When an electric dipole rotates in an oscillating electric field does it dissipate its potential energy in the form of heat or is that the heat that is dissipated is due to the collisions between molecules?? $\endgroup$ – Pradeep G Jun 21 '17 at 13:00
  • $\begingroup$ Look into Dielectric Loss - en.wikipedia.org/wiki/Dielectric_loss $\endgroup$ – vs_292 Jun 21 '17 at 16:09

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