According to Faraday's law of induction an electric field will be induced in a medium moving relative to a magnetic field. This induced electric field is proportional to the intensity of the magnetic field and to the relative velocity of the moving medium. When applied to media of arbitrary electrical conductivity and dielectric constant, it is seen that any potential difference that arises in connection with the induced electric field is attenuated by the shunting effect of the permittivity of free space. For most media this shunting effect is negligible; for media of extremely low conductivity, however, the effect is appreciable. Finally the effect of the electrical properties of the containing pipe is investigated.
REFERENCES
1.
M. Faraday, Phil. Tran. Roy. Soc. (London) Ser A, p. 125 (1832).
2.
C. Smith and J. Slepian, U.S. Patent No. 1,249,530 (1917).
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10.
A. Kolin, U.S. Patent No. 2,149,847 (1939).
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17.
W. K. H. Panofsky and M. Phillips, Classical Electricity and Magnetism (Addison‐Wesley Publishing Company, Inc., Cambridge, Massachusetts, 1955), p. 147.
18.
It might be noted that Lamb’s particular solution is the same as the general solution only if our fluid flows through an infinitely thick pipe which has the same electrical properties as the fluid.
19.
For the potential problem we have here, the boundary condition (38c) is obtained as follows. The equation of charge continuity provides . But Maxwell’s first equation allows this to be given as . But at our boundary we have , so that , and the boundary condition at is obtained in the usual fashion as , where denotes the normal component of E.
20.
W. K. H. Panofsky and M. Phillips, Classical Electricity and Magnetism (Addison‐Wesley Publishing Company, Inc., Cambridge Massachusetts, 1955), p. 65.
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© 1958 The American Institute of Physics.
1958
The American Institute of Physics
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