Dear Ask a Scholar: We are concerned about a potential power line 'upgrade' in the neighborhood, one which will increase the voltage from 69 kVto 115kV. With all the talk about health risks from EMF's (let's ignore the debate on that for the moment), wouldn’t a voltage increase from 69kV to 115kV cause an increase in EMFs? I realize that EMFs, or electromagnetic fields, are comprised of two separate things: an electric field and a magnetic field. Intuitively, I would think that the increase in voltage (I believe that the current lines are also being replaced with heavier ones) would cause an increase in EMF readings. What do you think?
Answered by NAS member Charles G. Beaudette, retired electrical engineer, and author of Excess Heat: Why Cold Fusion Research Prevailed.
Yes, the electromagnetic field will be larger --- approximately twice as great. But this assumes that the reading is taken at the same distance from the source as was the original reading. The two components of the field are not properly thought of as separate from one another. Although electric and magnetic are different kinds of fields, they are intertwined with one another. Also, we are talking here (in your question) about the "far field" from the wire. Close to the wire, there are strong and separate electric and magnetic fields.
With regard to the public debate: The effect on the questioner of raising the voltage will be that he may enjoy a more reliable source of electric power for his household and his hospital.
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