Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: veek on 07/11/2010 11:47:07
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Hi, I wanted to know if it's possible for a lady with bare-feet (grounded) to get electrocuted when stirring with a metal spoon while using an induction stove?
1. When the moving magnetic field engages with a ferro-magnetic cooking pot (iron), because iron is very permeable, a lot of flux lines are going to pass through the circular base of the stove. Because the intensity of flux changes (AC current passing through the inductor-coil) by Newtons 3rd law, an opposing current is setup within the base of the pot (eddy current) which generates an opposing magnetic field.
The 'skin effect' kicks in because the eddy currents are alternating (AC) therefore the eddy current gets pushed to a very narrow circular region at the base of the pot (this causes the heating effect).
Therefore, is there a dead-zone created within the base of the pot - with the eddy current forced into a very thin layer right at the very bottom of the metal container?? In which case, if I take a metal fork and stick it under the pot - i should get shocked?
2. Would an EMF/voltage (back-emf, from Lenz' law) be created at the base of the pot to account for the eddy current? Therefore touching the base would result in a potential difference between the pot-base (held at a higher potential due to back-emf) and your feet??
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It's very unlikely, the voltages produced in the metal are very low; it relies on the currents generated on very big thick bits of the pan. Also the frequency is fairly high, this means that the currents will flow around the cook, and avoid the heart due to 'skin effect'.
Also, the pan isn't usually earthed.