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Skin effect

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4105:) may be between 5 and 50 mm thick skin effect also occurs at sharp bends where the metal is compressed inside the bend and stretched outside the bend. The shorter path at the inner surface results in a lower resistance, which causes most of the current to be concentrated close to the inner bend surface. This causes an increase in temperature at that region compared with the straight (unbent) area of the same conductor. A similar skin effect occurs at the corners of rectangular conductors (viewed in cross-section), where the magnetic field is more concentrated at the corners than in the sides. This results in superior performance (i.e. higher current with lower temperature rise) from wide thin conductors (for example, 4128:
resistive losses affecting the accompanying eddy currents; skin effect confines such eddy currents to a very thin surface layer of the waveguide structure. Skin effect itself is not actually combatted in these cases, but the distribution of currents near the conductor's surface makes the use of precious metals (having a lower resistivity) practical. Although it has a lower conductivity than copper and silver, gold plating is also used, because unlike copper and silver, it does not corrode. A thin oxidized layer of copper or silver would have a low conductivity, and so would cause large power losses as the majority of the current would still flow through this layer.
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self-inductance) regardless of the wire's length, so that the inductance decrease due to skin effect can still be important. For instance, in the case of a telephone twisted pair, below, the inductance of the conductors substantially decreases at higher frequencies where skin effect becomes important. On the other hand, when the external component of the inductance is magnified due to the geometry of a coil (due to the mutual inductance between the turns), the significance of the internal inductance component is even further dwarfed and is ignored.
4070:, braided wire) is used to mitigate skin effect for frequencies of a few kilohertz to about one megahertz. It consists of a number of insulated wire strands woven together in a carefully designed pattern, so that the overall magnetic field acts equally on all the wires and causes the total current to be distributed equally among them. With skin effect having little effect on each of the thin strands, the bundle does not suffer the same increase in AC resistance that a solid conductor of the same cross-sectional area would due to skin effect. 2907: 4145: 39: 2891: 2971: 159: 4387: 1152:= 3 km). However, as the frequency is increased well into the megahertz range, its skin depth never falls below the asymptotic value of 11 meters. The conclusion is that in poor solid conductors, such as undoped silicon, skin effect does not need to be taken into account in most practical situations: Any current is equally distributed throughout the material's cross-section, regardless of its frequency. 27: 202:, are driven by an electric field due to the source of electrical energy. A current in a conductor produces a magnetic field in and around the conductor. When the intensity of current in a conductor changes, the magnetic field also changes. The change in the magnetic field, in turn, creates an electric field that opposes the change in current intensity. This opposing electric field is called 1045:(dependent on the density of free electrons in the material) and the reciprocal of the mean time between collisions involving the conduction electrons. In good conductors such as metals all of those conditions are ensured at least up to microwave frequencies, justifying this formula's validity. For example, in the case of copper, this would be true for frequencies much below 4098:
strength but low weight of tubes substantially increases span capability. Tubular conductors are typical in electric power switchyards where the distance between supporting insulators may be several meters. Long spans generally exhibit physical sag but this does not affect electrical performance. To avoid losses, the conductivity of the tube material must be high.
4190: 2052: 3637:). Since there is essentially no current deeper in the inner conductor, there is no magnetic field beneath the surface of the inner conductor. Since the current in the inner conductor is balanced by the opposite current flowing on the inside of the outer conductor, there is no remaining magnetic field in the outer conductor itself where 2883:(50 nH/m for non-magnetic wire) at low frequencies, regardless of the wire's radius. Its reduction with increasing frequency, as the ratio of skin depth to the wire's radius falls below about 1, is plotted in the accompanying graph, and accounts for the reduction in the telephone cable inductance with increasing frequency in the 4132:
results in fields and/or currents that oppose those generated by relatively nonmagnetic materials, but more work is needed to verify the exact mechanisms. As experiments have shown, this has potential to greatly improve the efficiency of conductors operating in tens of GHz or higher. This has strong ramifications for
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For a single wire, this reduction becomes of diminishing significance as the wire becomes longer in comparison to its diameter, and is usually neglected. However, the presence of a second conductor in the case of a transmission line reduces the extent of the external magnetic field (and of the total
3105:, however, there is a reduced magnetic field in the deeper sections of the inner conductor and the outer sections of the shield (outer conductor). Thus there is less energy stored in the magnetic field given the same total current, corresponding to a reduced inductance. At an even higher frequency, 1171:
Current density in round wire for various skin depths. Numbers shown on each curve are the ratio of skin depth to wire radius. The curve shown with the infinity sign is the zero frequency (DC) case. All curves are normalized so that the current density at the surface is the same. The horizontal
34:, current density decreases exponentially from the surface towards the inside. Skin depth, δ, is defined as the depth where the current density is just 1/e (about 37%) of the value at the surface; it depends on the frequency of the current and the electrical and magnetic properties of the conductor. 2934:
due to the portion of the magnetic field inside the wire itself, the green region in figure B. That small component of the inductance is reduced when the current is concentrated toward the skin of the conductor, that is, when skin depth is not much larger than the wire's radius, as will become the
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The inductance considered in this context refers to a bare conductor, not the inductance of a coil used as a circuit element. The inductance of a coil is dominated by the mutual inductance between the turns of the coil which increases its inductance according to the square of the number of turns.
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Recently, a method of layering non-magnetic and ferromagnetic materials with nanometer scale thicknesses has been shown to mitigate the increased resistance from skin effect for very high-frequency applications. A working theory is that the behavior of ferromagnetic materials in high frequencies
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frequencies where the small skin depth requires only a very thin layer of silver, making the improvement in conductivity very cost effective. Silver plating is similarly used on the surface of waveguides used for transmission of microwaves. This reduces attenuation of the propagating wave due to
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to increase their efficiency by mitigating both skin effect and proximity effect. Large power transformers are wound with stranded conductors of similar construction to litz wire, but employing a larger cross-section corresponding to the larger skin depth at mains frequencies. Conductive threads
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In applications where high currents (up to thousands of amperes) flow, solid conductors are usually replaced by tubes, eliminating the inner portion of the conductor where little current flows. This hardly affects the AC resistance, but considerably reduces the weight of the conductor. The high
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In a good conductor, skin depth is proportional to square root of the resistivity. This means that better conductors have a reduced skin depth. The overall resistance of the better conductor remains lower even with the reduced skin depth. However the better conductor will show a higher ratio
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This departure from the usual formula only applies for materials of rather low conductivity and at frequencies where the vacuum wavelength is not much larger than the skin depth itself. For instance, bulk silicon (undoped) is a poor conductor and has a skin depth of about 40 meters at
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Note that the above equation for the current density inside the conductor as a function of depth applies to cases where the usual approximation for skin depth holds. In the extreme cases where it doesn't, the exponential decrease with respect to skin depth still applies to the
4382:{\displaystyle {\begin{aligned}\delta &={\frac {1}{\alpha }}={\sqrt {{2\rho } \over {(2\pi f)(\mu _{0}\mu _{r})}}}\\&={\frac {1}{\sqrt {\pi f\mu \sigma }}}\approx 503\,{\sqrt {\frac {\rho }{\mu _{r}f}}}\approx 503\,{\frac {1}{\sqrt {\mu _{r}f\sigma }}},\end{aligned}}} 248:
is most often associated with applications involving transmission of electric currents, skin depth also describes the exponential decay of the electric and magnetic fields, as well as the density of induced currents, inside a bulk material when a plane wave impinges on it at
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but it is difficult to use them at frequencies much higher than 60 Hz. At a few kilohertz, an iron welding rod would glow red hot as current flows through the greatly increased AC resistance resulting from skin effect, with relatively little power remaining for the
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have been demonstrated as conductors for antennas from medium wave to microwave frequencies. Unlike standard antenna conductors, the nanotubes are much smaller than the skin depth, allowing full use of the thread's cross-section resulting in an extremely light antenna.
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The ratio AC resistance to DC resistance of a round wire versus the ratio of the wire's radius to the skin depth. As skin depth becomes small relative to the radius, the ratio of AC to DC resistance approaches one half of the ratio of the radius to the skin
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For a given current, the total energy stored in the magnetic fields must be the same as the calculated electrical energy attributed to that current flowing through the inductance of the coax; that energy is proportional to the cable's measured inductance.
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for alternating current at 60 Hz with a radius larger than one-third of an inch (8 mm) is a waste of copper, and in practice bus bars for heavy AC current are rarely more than half an inch (12 mm) thick except for mechanical reasons.
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Thus at microwave frequencies, most of the current flows in an extremely thin region near the surface. Ohmic losses of waveguides at microwave frequencies are therefore only dependent on the surface coating of the material. A layer of silver
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Refer to the diagram below showing the inner and outer conductors of a coaxial cable. Since skin effect causes a current at high frequencies to flow mainly at the surface of a conductor, it can be seen that this will reduce the magnetic field
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the wire, that is, beneath the depth at which the bulk of the current flows. It can be shown that this will have a minor effect on the self-inductance of the wire itself; see Skilling or Hayt for a mathematical treatment of this phenomenon.
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of the alternating current; as frequency increases, current flow becomes more concentrated near the surface, resulting in less skin depth. Skin effect reduces the effective cross-section of the conductor and thus increases its effective
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at 60 Hz. Iron wire is impractical for AC power lines (except to add mechanical strength by serving as a core to a non-ferromagnetic conductor like aluminum). Skin effect also reduces the effective thickness of
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inductance, the internal inductance is reduced by skin effect, that is, at frequencies where skin depth is no longer large compared to the conductor's size. This small component of inductance approaches a value of
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Conductors, typically in the form of wires, may be used to transfer electrical energy or signals using an alternating current flowing through that conductor. The charge carriers constituting that current, usually
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Although the geometry is different, a twisted pair used in telephone lines is similarly affected: at higher frequencies, the inductance decreases by more than 20% as can be seen in the following table.
352: 2484: 2116: 2838:; this accounts for the inductive reactance (imaginary part of the impedance) given by the above formula. In most cases this is a small portion of a wire's inductance which includes the effect of 2308: 5247:
These emf's are greater at the center than at the circumference, so the potential difference tends to establish currents that oppose the current at the center and assist it at the circumference.
4195: 4015:(1000 square millimeter) copper conductor has 23% more resistance than it does at DC. The same size conductor in aluminum has only 10% more resistance with 60 Hz AC than it does with DC. 848: 3866:
More extensive tables and tables for other gauges, temperatures and types are available in Reeve. Chen gives the same data in a parameterized form that he states is usable up to 50 MHz.
206:(back EMF). The back EMF is strongest / most concentrated at the center of the conductor, allowing current only near the outside skin of the conductor, as shown in the diagram on the right. 424:
and this very tiny phase velocity in a conductor, any wave entering a conductor, even at grazing incidence, refracts essentially in the direction perpendicular to the conductor's surface.
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skin depths, at which point the current density is attenuated to e (1.87×10, or −54.6 dB) of its surface value. The wavelength in the conductor is much shorter than the wavelength in
3613: 5086:, losses due to induced currents occur mostly within one skin depth of the surface. Thus, plating the surface of a waveguide with a material which has a low skin depth reduces losses. 4815:
At very high frequencies skin depth for good conductors becomes tiny. For instance, skin depths of some common metals at a frequency of 10 GHz (microwave region) are less than a
2701: 4657: 5080: 2881: 1823: 1087: 961: 49:) to reduce heating of the coil itself due to skin effect. The AC frequencies used in induction cookers are much higher than standard mains frequency ‒ typically around 25–50 kHz. 5175:
of the induced currents, however the imaginary part of the exponent in that equation, and thus the phase velocity inside the material, are altered with respect to that equation.
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The magnetic field inside a coaxial cable can be divided into three regions, each of which will therefore contribute to the electrical inductance seen by a length of cable.
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involving magnetic fields outside the wire (due to the total current in the wire) as seen in the white region of the figure below, there is also a much smaller component of
4772: 3668: 3314: 3248: 1522: 807: 2614: 2591: 2244: 2189: 1092: 1039: 1774: 3041:). The width of the dashed black lines is intended to show relative strength of the magnetic field integrated over the circumference at that radius. The four stages are 4652: 4504: 3081:, current covers the conductors uniformly and there is a significant magnetic field in all three regions. As the frequency is increased and the skin effect takes hold ( 779: 743: 4802: 4554: 4441: 4416: 3182: 1737: 1590: 1556: 626: 591: 4112:
It follows that a transformer with a round core will be more efficient than an equivalent-rated transformer having a square or rectangular core of the same material.
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of its value near the surface. Over 98% of the current will flow within a layer 4 times the skin depth from the surface. This behavior is distinct from that of
4529: 3427: 2479: 2313: 2143: 671: 529:{\displaystyle \delta ={\sqrt {{\frac {\,2\rho \,}{\omega \mu }}\left({\sqrt {1+\left({\rho \omega \varepsilon }\right)^{2}\,}}+\rho \omega \varepsilon \right)\,}}} 1411: 1384: 420:
of about 300 m, whereas in copper, the wavelength is reduced to only about 0.5 mm with a phase velocity of only about 500 m/s. As a consequence of
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Most discussions of coaxial transmission lines assume they will be used for radio frequencies, so equations are supplied corresponding only to the latter case.
2167: 1847: 646: 3113:, the skin depth is tiny: All current is confined to the surface of the conductors. The only magnetic field is in the regions between the conductors; only the 2959:
be the inner conductor radius, the shield (outer conductor) inside radius and the shield outer radius respectively, as seen in the crossection of figure 
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impinging on a conductor will therefore generally produce such a current; this explains the attenuation of electromagnetic waves in metals. Although the term
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high frequency. There are three regions that may contain induced magnetic fields: the center conductor, the dielectric and the outer conductor. In stage
5627:, Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, Vol. 215, No. 1123 (Dec. 22, 1952), pp. 481–497 (17 pages) 213:
is found to be greatest at the conductor's surface, with a reduced magnitude deeper in the conductor. That decline in current density is known as the
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axis is the position within the wire with the left and right extremes being the surface of the wire. The vertical axis is relative current density.
4094:; the higher resistance of the steel core is of no consequence since it is located far below the skin depth where essentially no AC current flows. 3507: 2894:
The internal component of a round wire's inductance vs. the ratio of skin depth to radius. That component of the self inductance is reduced below
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However, in very poor conductors, at sufficiently high frequencies, the factor under the large radical increases. At frequencies much higher than
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in 1940, who correctly suggested that it is due to the mean free path length of the electrons reaching the range of the classical skin depth.
2057: 1348:{\displaystyle \mathbf {J} (r)={\frac {k\mathbf {I} }{2\pi R}}{\frac {J_{0}(kr)}{J_{1}(kR)}}=\mathbf {J} (R){\frac {J_{0}(kr)}{J_{0}(kR)}}} 3097:) the magnetic field in the dielectric region is unchanged as it is proportional to the total current flowing in the center conductor. In 5025:. The intensity of the wave is proportional to the square of the amplitude, and thus the depth at which the intensity has diminished by 73:
is largest near the surface of the conductor and decreases exponentially with greater depths in the conductor. It is caused by opposing
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Four stages of skin effect in a coax showing the effect on inductance. Diagrams show a cross-section of the coaxial cable. Color code:
1164:. The current density inside round wire away from the influences of other fields, as function of distance from the axis is given by: 3996:{\displaystyle L(f)={\frac {\ell _{0}+\ell _{\infty }\left({\frac {f}{f_{m}}}\right)^{b}}{1+\left({\frac {f}{f_{m}}}\right)^{b}}}\,} 2425:
The most important effect of skin effect on the impedance of a single wire is the increase of the wire's resistance, and consequent
1670: 112:. Because the interior of a large conductor carries little of the current, tubular conductors can be used to save weight and cost. 4998:
In electromagnetic waves, the skin depth is the depth at which the amplitude of the electric and magnetic fields have reduced by
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its permeability is about 10,000 times greater. This reduces the skin depth for iron to about 1/38 that of copper, about 220
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as was pointed out above for the case of iron, despite its poorer conductivity. A practical consequence is seen by users of
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For high frequencies and low temperatures, the usual formulas for skin depth break down. This effect was first noticed by
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between its AC and DC resistance, when compared with a conductor of higher resistivity. For example, at 60 Hz, a
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is complex, the Bessel functions are also complex. The amplitude and phase of the current density varies with depth.
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This formula for the increase in AC resistance is accurate only for an isolated wire. For nearby wires, e.g. in a
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When skin depth is not small with respect to the radius of the wire, current density may be described in terms of
4171: 4019: 2558:{\displaystyle R\approx {{\ell \rho } \over {\pi (D-\delta )\delta }}\approx {{\ell \rho } \over {\pi D\delta }}} 2191:
is a constant phasor. To satisfy the boundary condition for the current density at the surface of the conductor,
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Skin depth vs. frequency for some materials at room temperature, red vertical line denotes 50 Hz frequency:
5872: 2429:. The effective resistance due to a current confined near the surface of a large conductor (much thicker than 378:
which is defined as the depth below the surface of the conductor at which the current density has fallen to 1/
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Increased AC resistance caused by skin effect can be mitigated by using a specialized multistrand wire called
4744:, about 9 times that of gold. Its skin depth at 50 Hz is likewise found to be about 33 mm, or 1858: 5055: 2854: 2437:
based on the DC resistivity of that material. The effective cross-sectional area is approximately equal to
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times the conductor's circumference. Thus a long cylindrical conductor such as a wire, having a diameter
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At 1 megahertz skin effect depth in wet soil is about 5.0 m; in seawater it is about 0.25 m.
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of the conductor. In the case of iron, its conductivity is about 1/7 that of copper. However being
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it can be shown that skin depth, rather than continuing to decrease, approaches an asymptotic value:
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Xi Nan; Sullivan, C. R. (2005). "An equivalent complex permeability model for litz-wire windings".
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Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005
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the quantity inside the large radical is close to unity and the formula is more usually given as:
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in copper, skin depth is about 8.5 mm. At high frequencies, skin depth becomes much smaller.
5511: 2801:{\displaystyle \mathbf {Z} _{\text{int}}={\frac {k\rho }{2\pi R}}{\frac {J_{0}(kR)}{J_{1}(kR)}}.} 1747: 146:
in 1883 for the case of spherical conductors, and was generalized to conductors of any shape by
4727:{\displaystyle \delta =503\,{\sqrt {\frac {2.44\cdot 10^{-8}}{1\cdot 50}}}=11.1\,\mathrm {mm} } 4627: 4479: 754: 718: 4780: 4536: 4423: 4398: 3621:
As skin effect increases, the currents are concentrated near the outside the inner conductor (
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is not changed by the skin effect and is given by the frequently cited formula for inductance
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would have a large imaginary part) and at frequencies that are much below both the material's
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This formula is valid at frequencies away from strong atomic or molecular resonances (where
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Representative parameter data for 24 gauge PIC telephone cable at 21 °C (70 °F).
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to take advantage of silver's higher conductivity. This technique is particularly used at
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thick evaporated on a piece of glass is thus an excellent conductor at such frequencies.
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Skin effect has practical consequences in the analysis and design of radio-frequency and
62: 31: 4591: 389:. The imaginary part of the exponent indicates that the phase of the current density is 5840: 5681: 5564: 5275:
To understand skin effect, you must first understand how eddy currents operate ...
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Lead, in contrast, is a relatively poor conductor (among metals) with a resistivity of
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of a wire of circular cross-section whose resistance will increase by 10% at frequency
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field resulting from the alternating current. The electric current flows mainly at the
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Highly magnetic materials have a reduced skin depth owing to their large permeability
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Distribution of current flow in a cylindrical conductor, shown in cross section. For
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In copper, skin depth can be seen to fall according to the square root of frequency:
2674:{\displaystyle D_{\mathrm {W} }={\frac {200~\mathrm {mm} }{\sqrt {f/\mathrm {Hz} }}}} 2054:
The solution to this equation is, for finite current in the center of the conductor,
1138:{\displaystyle \delta \approx {2\rho }{\sqrt {{\frac {\,\varepsilon \,}{\mu }}\,}}~.} 593: 266: 250: 193:
which partially cancel the current flow in the center and reinforce it near the skin.
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The general formula for skin depth when there is no dielectric or magnetic loss is:
19:"Skin depth" redirects here. For the depth (layers) of biological/organic skin, see 5814: 5779: 5548: 5205: 5196:
Lamb, Horace (1883-01-01). "XIII. On electrical motions in a spherical conductor".
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The formula as shown is algebraically equivalent to the formula found on page 130
2884: 4809: 4165: 4079: 1161: 210: 124: 70: 3250:, the region between the two conductors (containing a dielectric, possibly air). 2433:) can be solved as if the current flowed uniformly through a layer of thickness 4116: 4039: 3380:{\displaystyle L_{\text{total}}=L_{\text{cen}}+L_{\text{shd}}+L_{\text{ext}}\,} 2811: 1654:{\displaystyle k={\sqrt {\frac {-j\omega \mu }{\rho }}}={\frac {1-j}{\delta }}} 421: 410: 406: 226: 5552: 3495:{\displaystyle L/D={\frac {\mu _{0}}{2\pi }}\ln \left({\frac {b}{a}}\right)\,} 2406:{\displaystyle \mathbf {J} (r)=\mathbf {J} (R){\frac {J_{0}(kr)}{J_{0}(kR)}}.} 5861: 5836: 5818: 5560: 4023: 413:
in a vacuum. For example, a 1 MHz radio wave has a wavelength in vacuum
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which usually will be distributed evenly over the cross-section of the wire.
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At high frequencies, only the dielectric region has magnetic flux, so that
3564:{\displaystyle L_{\text{DC}}=L_{\text{cen}}+L_{\text{shd}}+L_{\text{ext}}\,} 236:
in a conductor due to an alternating magnetic field according to the law of
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conductors) in which the effects from corners are effectively eliminated.
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A portion of a wire's inductance can be attributed to the magnetic field
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contributes to the electrical inductance at these higher frequencies.
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However, when only a single wire is involved, then in addition to the
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At low frequencies, all three inductances are fully present so that
158: 2691:, which can cause an additional increase in the AC resistance. The 199: 135:
and distribution systems. It is one of the reasons for preferring
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of the conductor, between the outer surface and a level called the
78: 5537:"Study on Cu/Ni nano superlattice conductors for reduced RF loss" 4043: 3320:
The net electrical inductance is due to all three contributions:
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quantity corresponding to a resistance (real) in series with the
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Chen gives an equation of this form for telephone twisted pair:
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is associated with the magnetic field in the region with radius
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is a measure of the depth at which the current density falls to
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Feynman, Richard P; Leighton, Robert B; Sands, Matthew (1964).
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carrying direct current. The AC resistance of a wire of length
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1, so its skin depth at a frequency of 50 Hz is given by
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We can derive a practical formula for skin depth as follows:
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of the wire produced by the current in the wire. Unlike that
1705:{\displaystyle \delta ={\sqrt {\frac {2\rho }{\omega \mu }}}} 102: 26: 5512:"Spinning Carbon Nanotubes Spawns New Wireless Applications" 4881: 4836: 4101:
In high current situations where conductors (round or flat
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1 radian for each skin depth of penetration. One full
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cookware are unusable because they are not ferromagnetic.
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Litz wire is often used in the windings of high-frequency
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Vander Vorst, Andre; Rosen, Arye; Kotsuka, Youji (2006),
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Chapter 20,The Skin Effect, Introductory Electromagnetics
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Philosophical Transactions of the Royal Society of London
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Skin depth also varies as the inverse square root of the
347:{\displaystyle J=J_{\mathrm {S} }\,e^{-{(1+j)d/\delta }}} 5790: 5312: 2698:
per unit length of a segment of round wire is given by:
16:
Tendency of AC current flow in a conductor's outer layer
4133: 2111:{\displaystyle \mathbf {J} (r)=\mathbf {C} J_{0}(kr),} 5058: 5031: 5004: 4783: 4750: 4660: 4630: 4594: 4562: 4539: 4514: 4482: 4449: 4426: 4401: 4193: 3875: 3676: 3643: 3580: 3510: 3430: 3394: 3326: 3289: 3261: 3223: 3195: 3163: 3135: 2902:
as skin depth becomes small (as frequency increases).
2857: 2704: 2617: 2573: 2487: 2467: 2316: 2303:{\displaystyle {\frac {\mathbf {J} (R)}{J_{0}(kR)}}.} 2252: 2230: 2197: 2175: 2155: 2124: 2060: 1871: 1835: 1788: 1750: 1720: 1673: 1600: 1566: 1532: 1505: 1467: 1421: 1394: 1367: 1181: 1095: 1058: 1027: 969: 932: 893: 857: 818: 792: 757: 721: 682: 656: 634: 602: 576: 548: 433: 360: 286: 168:
flowing through a conductor induces a magnetic field
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was developed for this specific case for metals and
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is associated with the magnetic field in the region
3217:
is associated with the magnetic field in the region
5530: 5528: 3031:coming out of the diagram, dashed black lines with 5680: 5342:Transmission and Distribution of Electrical Energy 5261:High-Speed Signal propagation Advanced Black Magic 5074: 5044: 5017: 4796: 4766: 4726: 4646: 4603: 4571: 4548: 4523: 4498: 4467: 4435: 4410: 4381: 4066:A type of cable called litz wire (from the German 3995: 3689: 3662: 3607: 3563: 3494: 3408: 3379: 3308: 3275: 3242: 3209: 3176: 3149: 2875: 2800: 2673: 2585: 2557: 2473: 2405: 2302: 2238: 2217: 2183: 2161: 2137: 2110: 2046: 1841: 1817: 1768: 1731: 1704: 1653: 1584: 1550: 1516: 1489: 1443: 1405: 1378: 1347: 1137: 1081: 1033: 1011: 955: 909: 873: 843:{\displaystyle \varepsilon _{r}\,\varepsilon _{0}} 842: 801: 773: 737: 706: 665: 640: 620: 585: 557: 528: 366: 346: 5462:(11th ed.), McGraw Hill, p. Table 18–21 2687:or a coil, the AC resistance is also affected by 1497:current density phasor at the surface of the wire 5859: 5793:RF/Microwave Interaction with Biological Tissues 5525: 5458:Fink, Donald G.; Beatty, H. Wayne, eds. (1978), 5153:, a method for estimating skin effect resistance 4035:in power transformers, increasing their losses. 4005: 5381: 5263:(3rd ed.). Prentice Hall. pp. 58–78. 4616:Gold is a good conductor with a resistivity of 5808: 5751: 5541:IEEE Microwave and Wireless Components Letters 5484: 5472: 5335: 5333: 5496:Central Electricity Generating Board (1982). 5258: 5235:(14th ed.). McGraw-Hill. pp. 2–50. 142:The effect was first described in a paper by 5428:harvtxt error: no target: CITEREFReeve1995 ( 5306: 4979:, Hayt points out that in a power station a 4556:the conductivity of the medium (for copper, 4092:aluminum cable with a steel reinforcing core 3608:{\displaystyle L_{\infty }=L_{\text{ext}}\,} 2818:(imaginary) due to the wire's internal self- 409:in a conductor is very much slower than the 180:induces separate, circulating eddy currents 5721:Electromagnetic Waves and Radiating Systems 5393: 5330: 5534: 5460:Standard Handbook for Electrical Engineers 5457: 5252: 5233:Standard Handbook for Electrical Engineers 4115:Solid or tubular conductors may be silver- 4055:rods are used for high-frequency welding. 2453:that of a hollow tube with wall thickness 1592:Bessel function of the first kind, order 1 1558:Bessel function of the first kind, order 0 5489: 5441: 5439: 5231:Fink, Donald G.; Beaty, H. Wayne (2000). 5230: 4715: 4670: 4346: 4315: 3992: 3659: 3604: 3560: 3491: 3405: 3376: 3316:, the region inside the shield conductor. 3305: 3272: 3239: 3206: 3184:, the region inside the center conductor. 3173: 3146: 1126: 1119: 1115: 1000: 988: 981: 829: 693: 523: 503: 452: 445: 305: 5769: 5661:The Feynman Lectures on Physics Volume 2 5417: 5387: 5313:Vander Vorst, Rosen & Kotsuka (2006) 5259:Johnson, Howard; Graham, Martin (2003). 5089: 4987: 4143: 2969: 2905: 2889: 1166: 157: 37: 25: 5752:Popovic, Zoya; Popovic, Branko (1999), 5700: 5657: 5611: 5599: 5405: 5369: 5860: 5778: 5718: 5535:Rahimi, A.; Yoon, Y.-K. (2016-03-16). 5436: 5363: 5324: 2567:The final approximation above assumes 139:for long-distance power transmission. 5423: 5339: 5317: 5280: 5075:{\displaystyle {\frac {\delta }{2}}.} 4825:Skin depths at microwave frequencies 2876:{\displaystyle {\frac {\mu }{8\pi }}} 1818:{\displaystyle \mu =\mu _{r}\mu _{0}} 1082:{\displaystyle 1/(\rho \varepsilon )} 956:{\displaystyle 1/(\rho \varepsilon )} 209:Regardless of the driving force, the 162:Cause of skin effect. A main current 5678: 5639: 5587: 5445: 5411: 5399: 5375: 5286: 5195: 4919:8420       4911:9220       2834:the wire itself which is termed the 2596:A convenient formula (attributed to 65:(AC) to become distributed within a 5813:. Vol. 3. pp. 2229–2235. 5151:Wheeler incremental inductance rule 5116:Proximity effect (electromagnetism) 4935:206       4927:652       232:An alternating current may also be 13: 5738:Oliver Heaviside: Sage in Solitude 5629:https://www.jstor.org/stable/99095 4720: 4717: 4611:the frequency of the current in Hz 3912: 3704: 3586: 2664: 2661: 2646: 2643: 2624: 1988: 1984: 1939: 1929: 1873: 1490:{\displaystyle \mathbf {J} (R)={}} 1444:{\displaystyle \mathbf {J} (r)={}} 1386:distance from the axis of the wire 707:{\displaystyle \mu _{r}\,\mu _{0}} 299: 14: 5884: 5853: 2147:Bessel function of the first kind 910:{\displaystyle \varepsilon _{0}=} 874:{\displaystyle \varepsilon _{r}=} 4624:and is essentially nonmagnetic: 3629:) and the inside of the shield ( 3409:{\displaystyle L_{\text{ext}}\,} 3276:{\displaystyle L_{\text{shd}}\,} 3210:{\displaystyle L_{\text{ext}}\,} 3150:{\displaystyle L_{\text{cen}}\,} 2942: 2707: 2335: 2318: 2257: 2232: 2218:{\displaystyle \mathbf {J} (R),} 2199: 2177: 2079: 2062: 2025: 1998: 1956: 1910: 1883: 1507: 1469: 1423: 1280: 1206: 1183: 5617: 5605: 5593: 5581: 5504: 5478: 5466: 5451: 4572:{\displaystyle \sigma \approx } 4468:{\displaystyle {\frac {Np}{m}}} 4172:grain-oriented electrical steel 5740:. New York: IEEE Press, 1988. 5719:Jordan, Edward Conrad (1968), 5514:. Sciencedaily.com. 2009-03-09 5357: 5189: 5164: 5045:{\displaystyle {\frac {1}{e}}} 5018:{\displaystyle {\frac {1}{e}}} 4531:the permeability of the medium 4506:the permeability of free space 4271: 4248: 4245: 4233: 3885: 3879: 3690:{\displaystyle L_{\text{ext}}} 2789: 2780: 2765: 2756: 2520: 2508: 2394: 2385: 2370: 2361: 2345: 2339: 2328: 2322: 2291: 2282: 2267: 2261: 2209: 2203: 2102: 2093: 2072: 2066: 2035: 2029: 2008: 2002: 1966: 1960: 1920: 1914: 1893: 1887: 1479: 1473: 1433: 1427: 1339: 1330: 1315: 1306: 1290: 1284: 1270: 1261: 1246: 1237: 1193: 1187: 1076: 1067: 950: 941: 327: 315: 280:from the surface, as follows: 269:from its value at the surface 1: 5795:, John Wiley and Sons, Inc., 5687:(4th ed.), McGraw-Hill, 5498:Modern Power Station Practice 5293:(5th ed.), McGraw-Hill, 5182: 4767:{\displaystyle {\sqrt {9}}=3} 4061: 4006:Material effect on skin depth 3663:{\displaystyle b<r<c\,} 3309:{\displaystyle b<r<c\,} 3243:{\displaystyle a<r<b\,} 2825: 2420: 1859:electromagnetic wave equation 1852: 1517:{\displaystyle \mathbf {I} =} 1155: 802:{\displaystyle \varepsilon =} 5701:Jackson, John David (1999), 5683:Engineering Electromagnetics 5290:Engineering Electromagnetics 4977:Engineering Electromagnetics 2935:case at higher frequencies. 2586:{\displaystyle D\gg \delta } 2415: 2239:{\displaystyle \mathbf {C} } 2184:{\displaystyle \mathbf {C} } 1034:{\displaystyle \varepsilon } 63:alternating electric current 7: 5772:Electric Transmission Lines 5109: 4139: 4086:High-voltage, high-current 1769:{\displaystyle \mu _{r}={}} 1459:, from the axis of the wire 397:in the conductor requires 2 204:counter-electromotive force 137:high-voltage direct current 133:electric power transmission 10: 5889: 5770:Skilling, Hugh H. (1951), 5485:Xi Nan & Sullivan 2005 5473:Popovic & Popovic 1999 4991: 4176:Fe-Ni – high-permeability 4152:Mn-Zn – magnetically soft 926:At frequencies much below 919:permittivity of free space 783:permeability of free space 256: 127:. It is also important at 92:Skin depth depends on the 18: 5784:Radio Engineers' Handbook 5703:Classical Electrodynamics 5625:The Anomalous Skin Effect 5577:– via ResearchGate. 5553:10.1109/LMWC.2016.2537780 5340:Weeks, Walter L. (1981), 5287:Hayt, William H. (1989), 4647:{\displaystyle \mu _{r}=} 4499:{\displaystyle \mu _{0}=} 774:{\displaystyle \mu _{0}=} 738:{\displaystyle \mu _{r}=} 5819:10.1109/IAS.2005.1518758 5640:Chen, Walter Y. (2004), 5157: 5146:Magnetic Reynolds number 4916:60  Hz   4908:50  Hz   4797:{\displaystyle \mu _{r}} 4549:{\displaystyle \sigma =} 4436:{\displaystyle \alpha =} 4418:the skin depth in meters 4411:{\displaystyle \delta =} 4038:Iron rods work well for 3177:{\displaystyle r<a\,} 1732:{\displaystyle \rho ={}} 1585:{\displaystyle J_{1}={}} 1551:{\displaystyle J_{0}={}} 621:{\displaystyle =2\pi f,} 586:{\displaystyle \omega =} 153: 77:induced by the changing 5786:, New York: McGraw-Hill 5705:(3rd ed.), Wiley, 3744:1  Hz   1712:also called skin depth. 405:, or equivalently, the 367:{\displaystyle \delta } 276:according to the depth 267:decreases exponentially 261:The AC current density 5679:Hayt, William (1981), 5642:Home Networking Basics 5210:10.1098/rstl.1883.0013 5076: 5046: 5019: 4808:, where some types of 4798: 4768: 4728: 4648: 4605: 4573: 4550: 4525: 4500: 4469: 4437: 4412: 4383: 4184: 4158:Al – metallic aluminum 3997: 3691: 3664: 3609: 3565: 3496: 3410: 3381: 3310: 3277: 3244: 3211: 3178: 3151: 3118: 3065:middle frequency, and 2912: 2903: 2877: 2802: 2675: 2587: 2559: 2475: 2407: 2304: 2240: 2219: 2185: 2163: 2139: 2112: 2048: 1843: 1819: 1770: 1733: 1706: 1655: 1586: 1552: 1518: 1491: 1445: 1407: 1380: 1349: 1173: 1139: 1083: 1035: 1013: 957: 911: 875: 844: 803: 775: 739: 708: 667: 642: 622: 587: 559: 558:{\displaystyle \rho =} 530: 368: 348: 194: 131:(50–60 Hz) in AC 61:is the tendency of an 50: 35: 5873:Electrical parameters 5100:Mattis–Bardeen theory 5090:Anomalous skin effect 5077: 5047: 5020: 4988:Electromagnetic waves 4893:Skin depth in copper 4799: 4769: 4729: 4649: 4606: 4574: 4551: 4526: 4524:{\displaystyle \mu =} 4501: 4470: 4438: 4413: 4384: 4164:steel 410 – magnetic 4147: 3998: 3692: 3665: 3610: 3566: 3497: 3411: 3382: 3311: 3278: 3245: 3212: 3179: 3152: 3033:arrowheads = magnetic 2973: 2909: 2893: 2878: 2842:from magnetic fields 2803: 2676: 2588: 2560: 2476: 2474:{\displaystyle \rho } 2408: 2305: 2241: 2220: 2186: 2164: 2140: 2138:{\displaystyle J_{0}} 2113: 2049: 1844: 1820: 1778:magnetic permeability 1771: 1734: 1707: 1656: 1587: 1553: 1519: 1492: 1446: 1408: 1381: 1350: 1170: 1140: 1084: 1036: 1014: 958: 912: 876: 845: 804: 776: 747:magnetic permeability 740: 709: 668: 666:{\displaystyle \mu =} 643: 623: 588: 560: 531: 369: 349: 161: 123:(or waveguides), and 41: 29: 5344:, Harper & Row, 5056: 5029: 5002: 4956:100 MHz   4932:100 kHz   4781: 4774:times that of gold. 4748: 4658: 4628: 4592: 4560: 4537: 4512: 4480: 4447: 4424: 4399: 4191: 4161:Cu – metallic copper 4088:overhead power lines 3873: 3795:100 kHz   3674: 3641: 3578: 3508: 3428: 3424:of a coaxial cable: 3392: 3324: 3287: 3259: 3221: 3193: 3161: 3133: 2855: 2810:This impedance is a 2702: 2615: 2571: 2485: 2465: 2314: 2250: 2228: 2195: 2173: 2153: 2122: 2058: 1869: 1833: 1786: 1748: 1718: 1671: 1598: 1564: 1530: 1524:total current phasor 1503: 1465: 1419: 1406:{\displaystyle R={}} 1392: 1379:{\displaystyle r={}} 1365: 1179: 1093: 1056: 1025: 967: 930: 891: 855: 816: 790: 755: 719: 680: 654: 632: 600: 574: 546: 431: 358: 284: 242:electromagnetic wave 45:use stranded coils ( 5402:, pp. 434–439) 5390:, pp. 157–159) 4948:10 MHz   4924:10 kHz   4894: 4826: 4443:the attenuation in 3778:10 kHz   3115:external inductance 2983:insulating sheath, 2947:Let the dimensions 2932:internal inductance 2928:external inductance 2836:internal inductance 2822:, per unit length. 2600:) for the diameter 2449:, has a resistance 32:alternating current 5664:. Addison-Wesley. 5072: 5042: 5015: 4964:1 GHz   4951:20.6    4943:65.2    4940:1 MHz   4892: 4824: 4794: 4764: 4724: 4644: 4604:{\displaystyle f=} 4601: 4569: 4546: 4521: 4496: 4465: 4433: 4408: 4379: 4377: 4185: 3993: 3846:5 MHz   3829:2 MHz   3812:1 MHz   3761:1 kHz   3687: 3660: 3605: 3561: 3492: 3406: 3377: 3306: 3273: 3240: 3207: 3174: 3147: 3119: 3020:into the diagram, 2913: 2904: 2873: 2798: 2671: 2583: 2555: 2471: 2445:large compared to 2403: 2300: 2236: 2215: 2181: 2159: 2135: 2108: 2044: 1839: 1815: 1766: 1729: 1702: 1651: 1582: 1548: 1514: 1487: 1441: 1413:radius of the wire 1403: 1376: 1345: 1174: 1135: 1079: 1031: 1009: 953: 907: 871: 840: 812:of the conductor, 799: 771: 735: 704: 676:of the conductor, 663: 638: 618: 583: 555: 526: 364: 344: 195: 121:transmission lines 51: 36: 5828:978-0-7803-9208-3 5802:978-0-471-73277-8 5763:978-0-201-32678-9 5756:, Prentice-Hall, 5730:978-0-13-249995-8 5723:, Prentice Hall, 5694:978-0-07-027395-5 5651:978-0-13-016511-4 5644:, Prentice Hall, 5500:. Pergamon Press. 5270:978-0-13-084408-8 5242:978-0-07-022005-8 5141:Induction heating 5136:Induction cooking 5067: 5040: 5013: 4994:Penetration depth 4971: 4970: 4875: 4874: 4806:induction cookers 4756: 4707: 4706: 4463: 4370: 4369: 4338: 4337: 4307: 4306: 4276: 4275: 4216: 3990: 3977: 3937: 3862: 3861: 3684: 3601: 3557: 3544: 3531: 3518: 3485: 3465: 3402: 3373: 3360: 3347: 3334: 3269: 3203: 3143: 2871: 2793: 2741: 2714: 2669: 2668: 2641: 2553: 2527: 2398: 2295: 2162:{\displaystyle 0} 1995: 1980: 1953: 1842:{\displaystyle k} 1700: 1699: 1649: 1628: 1627: 1343: 1274: 1222: 1131: 1127: 1124: 1005: 1001: 998: 648:is the frequency. 641:{\displaystyle f} 594:angular frequency 524: 504: 462: 129:mains frequencies 43:Induction cookers 5880: 5868:Electromagnetism 5848: 5805: 5787: 5775: 5766: 5733: 5715: 5697: 5686: 5675: 5654: 5631: 5623:R. G. Chambers, 5621: 5615: 5614:, p. 32-11) 5609: 5603: 5597: 5591: 5585: 5579: 5578: 5576: 5575: 5532: 5523: 5522: 5520: 5519: 5508: 5502: 5501: 5493: 5487: 5482: 5476: 5470: 5464: 5463: 5455: 5449: 5443: 5434: 5433: 5421: 5415: 5409: 5403: 5397: 5391: 5385: 5379: 5373: 5367: 5361: 5355: 5354: 5337: 5328: 5321: 5315: 5310: 5304: 5303: 5284: 5278: 5277: 5256: 5250: 5249: 5228: 5222: 5221: 5193: 5176: 5168: 5081: 5079: 5078: 5073: 5068: 5060: 5051: 5049: 5048: 5043: 5041: 5033: 5024: 5022: 5021: 5016: 5014: 5006: 4895: 4891: 4827: 4823: 4803: 4801: 4800: 4795: 4793: 4792: 4773: 4771: 4770: 4765: 4757: 4752: 4743: 4741: 4733: 4731: 4730: 4725: 4723: 4708: 4705: 4694: 4693: 4692: 4673: 4672: 4653: 4651: 4650: 4645: 4640: 4639: 4623: 4621: 4610: 4608: 4607: 4602: 4585: 4583: 4578: 4576: 4575: 4570: 4555: 4553: 4552: 4547: 4530: 4528: 4527: 4522: 4505: 4503: 4502: 4497: 4492: 4491: 4474: 4472: 4471: 4466: 4464: 4459: 4451: 4442: 4440: 4439: 4434: 4417: 4415: 4414: 4409: 4388: 4386: 4385: 4380: 4378: 4371: 4362: 4361: 4352: 4348: 4339: 4336: 4332: 4331: 4318: 4317: 4308: 4293: 4289: 4281: 4277: 4274: 4270: 4269: 4260: 4259: 4231: 4223: 4222: 4217: 4209: 4136:communications. 4080:carbon nanotubes 4002: 4000: 3999: 3994: 3991: 3989: 3988: 3987: 3982: 3978: 3976: 3975: 3963: 3949: 3948: 3947: 3942: 3938: 3936: 3935: 3923: 3916: 3915: 3903: 3902: 3892: 3714: 3713: 3696: 3694: 3693: 3688: 3686: 3685: 3682: 3669: 3667: 3666: 3661: 3614: 3612: 3611: 3606: 3603: 3602: 3599: 3590: 3589: 3570: 3568: 3567: 3562: 3559: 3558: 3555: 3546: 3545: 3542: 3533: 3532: 3529: 3520: 3519: 3516: 3501: 3499: 3498: 3493: 3490: 3486: 3478: 3466: 3464: 3456: 3455: 3446: 3438: 3415: 3413: 3412: 3407: 3404: 3403: 3400: 3386: 3384: 3383: 3378: 3375: 3374: 3371: 3362: 3361: 3358: 3349: 3348: 3345: 3336: 3335: 3332: 3315: 3313: 3312: 3307: 3282: 3280: 3279: 3274: 3271: 3270: 3267: 3255:The inductance 3249: 3247: 3246: 3241: 3216: 3214: 3213: 3208: 3205: 3204: 3201: 3189:The inductance 3183: 3181: 3180: 3175: 3156: 3154: 3153: 3148: 3145: 3144: 3141: 3129:The inductance 3111: 3110: 3103: 3102: 3095: 3094: 3087: 3086: 3079: 3078: 3071: 3070: 3063: 3062: 3055: 3054: 3047: 3046: 3039: 3034: 3030: 3028: 3027: 3019: 3017: 3016: 3008: 3006: 3004: 3003: 2993: 2991: 2990: 2982: 2980: 2965: 2964: 2958: 2954: 2950: 2901: 2882: 2880: 2879: 2874: 2872: 2870: 2859: 2807: 2805: 2804: 2799: 2794: 2792: 2779: 2778: 2768: 2755: 2754: 2744: 2742: 2740: 2729: 2721: 2716: 2715: 2712: 2710: 2689:proximity effect 2680: 2678: 2677: 2672: 2670: 2667: 2659: 2651: 2650: 2649: 2639: 2634: 2629: 2628: 2627: 2610: 2603: 2592: 2590: 2589: 2584: 2564: 2562: 2561: 2556: 2554: 2552: 2541: 2533: 2528: 2526: 2503: 2495: 2480: 2478: 2477: 2472: 2461:and resistivity 2460: 2456: 2448: 2444: 2440: 2436: 2432: 2412: 2410: 2409: 2404: 2399: 2397: 2384: 2383: 2373: 2360: 2359: 2349: 2338: 2321: 2309: 2307: 2306: 2301: 2296: 2294: 2281: 2280: 2270: 2260: 2254: 2245: 2243: 2242: 2237: 2235: 2224: 2222: 2221: 2216: 2202: 2190: 2188: 2187: 2182: 2180: 2168: 2166: 2165: 2160: 2144: 2142: 2141: 2136: 2134: 2133: 2117: 2115: 2114: 2109: 2092: 2091: 2082: 2065: 2053: 2051: 2050: 2045: 2028: 2023: 2022: 2001: 1996: 1994: 1983: 1981: 1973: 1959: 1954: 1952: 1951: 1950: 1937: 1936: 1927: 1913: 1908: 1907: 1886: 1881: 1880: 1848: 1846: 1845: 1840: 1824: 1822: 1821: 1816: 1814: 1813: 1804: 1803: 1780:of the conductor 1775: 1773: 1772: 1767: 1765: 1760: 1759: 1742:of the conductor 1738: 1736: 1735: 1730: 1728: 1711: 1709: 1708: 1703: 1701: 1698: 1690: 1682: 1681: 1665:in the conductor 1660: 1658: 1657: 1652: 1650: 1645: 1634: 1629: 1623: 1609: 1608: 1591: 1589: 1588: 1583: 1581: 1576: 1575: 1557: 1555: 1554: 1549: 1547: 1542: 1541: 1523: 1521: 1520: 1515: 1510: 1496: 1494: 1493: 1488: 1486: 1472: 1451:current density 1450: 1448: 1447: 1442: 1440: 1426: 1412: 1410: 1409: 1404: 1402: 1385: 1383: 1382: 1377: 1375: 1354: 1352: 1351: 1346: 1344: 1342: 1329: 1328: 1318: 1305: 1304: 1294: 1283: 1275: 1273: 1260: 1259: 1249: 1236: 1235: 1225: 1223: 1221: 1210: 1209: 1200: 1186: 1162:Bessel functions 1151: 1144: 1142: 1141: 1136: 1129: 1128: 1125: 1120: 1113: 1111: 1109: 1088: 1086: 1085: 1080: 1066: 1048: 1043:plasma frequency 1040: 1038: 1037: 1032: 1018: 1016: 1015: 1010: 1003: 1002: 999: 997: 989: 979: 977: 962: 960: 959: 954: 940: 916: 914: 913: 908: 903: 902: 885:of the conductor 880: 878: 877: 872: 867: 866: 849: 847: 846: 841: 839: 838: 828: 827: 808: 806: 805: 800: 780: 778: 777: 772: 767: 766: 749:of the conductor 744: 742: 741: 736: 731: 730: 713: 711: 710: 705: 703: 702: 692: 691: 672: 670: 669: 664: 647: 645: 644: 639: 627: 625: 624: 619: 592: 590: 589: 584: 568:of the conductor 564: 562: 561: 556: 535: 533: 532: 527: 525: 522: 518: 505: 502: 501: 496: 492: 470: 463: 461: 453: 443: 441: 416: 400: 385: 382:(about 0.37) of 373: 371: 370: 365: 353: 351: 350: 345: 343: 342: 341: 337: 304: 303: 302: 279: 272: 264: 251:normal incidence 191: 190: 184: 178: 172: 166: 148:Oliver Heaviside 55:electromagnetism 5888: 5887: 5883: 5882: 5881: 5879: 5878: 5877: 5858: 5857: 5856: 5851: 5829: 5803: 5764: 5736:Nahin, Paul J. 5731: 5713: 5695: 5672: 5652: 5635: 5634: 5622: 5618: 5610: 5606: 5598: 5594: 5590:, pp. 401) 5586: 5582: 5573: 5571: 5533: 5526: 5517: 5515: 5510: 5509: 5505: 5494: 5490: 5483: 5479: 5471: 5467: 5456: 5452: 5444: 5437: 5427: 5422: 5418: 5410: 5406: 5398: 5394: 5386: 5382: 5378:, pp. 303) 5374: 5370: 5362: 5358: 5352: 5338: 5331: 5322: 5318: 5311: 5307: 5301: 5285: 5281: 5271: 5257: 5253: 5243: 5229: 5225: 5194: 5190: 5185: 5180: 5179: 5169: 5165: 5160: 5112: 5104:superconductors 5092: 5059: 5057: 5054: 5053: 5032: 5030: 5027: 5026: 5005: 5003: 5000: 4999: 4996: 4990: 4902: 4834: 4810:stainless steel 4788: 4784: 4782: 4779: 4778: 4751: 4749: 4746: 4745: 4739: 4737: 4716: 4695: 4685: 4681: 4674: 4671: 4659: 4656: 4655: 4635: 4631: 4629: 4626: 4625: 4619: 4617: 4614: 4593: 4590: 4589: 4581: 4579: 4561: 4558: 4557: 4538: 4535: 4534: 4513: 4510: 4509: 4487: 4483: 4481: 4478: 4477: 4452: 4450: 4448: 4445: 4444: 4425: 4422: 4421: 4400: 4397: 4396: 4376: 4375: 4357: 4353: 4347: 4327: 4323: 4322: 4316: 4288: 4279: 4278: 4265: 4261: 4255: 4251: 4232: 4224: 4221: 4208: 4201: 4194: 4192: 4189: 4188: 4183: 4166:stainless steel 4142: 4064: 4008: 3983: 3971: 3967: 3962: 3958: 3957: 3950: 3943: 3931: 3927: 3922: 3918: 3917: 3911: 3907: 3898: 3894: 3893: 3891: 3874: 3871: 3870: 3738: 3733: 3728: 3723: 3718: 3707: 3705:Telephone cable 3681: 3677: 3675: 3672: 3671: 3642: 3639: 3638: 3598: 3594: 3585: 3581: 3579: 3576: 3575: 3554: 3550: 3541: 3537: 3528: 3524: 3515: 3511: 3509: 3506: 3505: 3477: 3473: 3457: 3451: 3447: 3445: 3434: 3429: 3426: 3425: 3399: 3395: 3393: 3390: 3389: 3370: 3366: 3357: 3353: 3344: 3340: 3331: 3327: 3325: 3322: 3321: 3288: 3285: 3284: 3266: 3262: 3260: 3257: 3256: 3222: 3219: 3218: 3200: 3196: 3194: 3191: 3190: 3162: 3159: 3158: 3140: 3136: 3134: 3131: 3130: 3108: 3107: 3100: 3099: 3092: 3091: 3084: 3083: 3076: 3075: 3068: 3067: 3060: 3059: 3057:low frequency, 3052: 3051: 3049:non-energized, 3044: 3043: 3037: 3032: 3023: 3022: 3021: 3012: 3011: 3010: 2999: 2998: 2996: 2995: 2986: 2985: 2984: 2976: 2975: 2962: 2961: 2956: 2952: 2948: 2945: 2915: 2899: 2863: 2858: 2856: 2853: 2852: 2828: 2774: 2770: 2769: 2750: 2746: 2745: 2743: 2730: 2722: 2720: 2711: 2706: 2705: 2703: 2700: 2699: 2660: 2655: 2642: 2635: 2633: 2623: 2622: 2618: 2616: 2613: 2612: 2608: 2606: 2601: 2572: 2569: 2568: 2542: 2534: 2532: 2504: 2496: 2494: 2486: 2483: 2482: 2466: 2463: 2462: 2458: 2454: 2446: 2442: 2438: 2434: 2430: 2423: 2418: 2379: 2375: 2374: 2355: 2351: 2350: 2348: 2334: 2317: 2315: 2312: 2311: 2276: 2272: 2271: 2256: 2255: 2253: 2251: 2248: 2247: 2231: 2229: 2226: 2225: 2198: 2196: 2193: 2192: 2176: 2174: 2171: 2170: 2154: 2151: 2150: 2129: 2125: 2123: 2120: 2119: 2087: 2083: 2078: 2061: 2059: 2056: 2055: 2024: 2018: 2014: 1997: 1987: 1982: 1972: 1955: 1946: 1942: 1938: 1932: 1928: 1926: 1909: 1903: 1899: 1882: 1876: 1872: 1870: 1867: 1866: 1855: 1834: 1831: 1830: 1827: 1809: 1805: 1799: 1795: 1787: 1784: 1783: 1764: 1755: 1751: 1749: 1746: 1745: 1727: 1719: 1716: 1715: 1691: 1683: 1680: 1672: 1669: 1668: 1635: 1633: 1610: 1607: 1599: 1596: 1595: 1580: 1571: 1567: 1565: 1562: 1561: 1546: 1537: 1533: 1531: 1528: 1527: 1506: 1504: 1501: 1500: 1485: 1468: 1466: 1463: 1462: 1439: 1422: 1420: 1417: 1416: 1401: 1393: 1390: 1389: 1374: 1366: 1363: 1362: 1324: 1320: 1319: 1300: 1296: 1295: 1293: 1279: 1255: 1251: 1250: 1231: 1227: 1226: 1224: 1211: 1205: 1201: 1199: 1182: 1180: 1177: 1176: 1158: 1149: 1114: 1112: 1110: 1102: 1094: 1091: 1090: 1062: 1057: 1054: 1053: 1046: 1026: 1023: 1022: 990: 980: 978: 976: 968: 965: 964: 936: 931: 928: 927: 924: 898: 894: 892: 889: 888: 862: 858: 856: 853: 852: 834: 830: 823: 819: 817: 814: 813: 791: 788: 787: 762: 758: 756: 753: 752: 726: 722: 720: 717: 716: 698: 694: 687: 683: 681: 678: 677: 655: 652: 651: 633: 630: 629: 601: 598: 597: 575: 572: 571: 547: 544: 543: 497: 482: 478: 477: 469: 468: 464: 454: 444: 442: 440: 432: 429: 428: 419: 414: 398: 388: 383: 359: 356: 355: 333: 314: 310: 306: 298: 297: 293: 285: 282: 281: 277: 275: 270: 265:in a conductor 262: 259: 211:current density 192: 188: 187: 182: 176: 170: 164: 156: 71:current density 24: 17: 12: 11: 5: 5886: 5876: 5875: 5870: 5855: 5854:External links 5852: 5850: 5849: 5827: 5806: 5801: 5788: 5776: 5767: 5762: 5749: 5734: 5729: 5716: 5712:978-0471309321 5711: 5698: 5693: 5676: 5670: 5655: 5650: 5636: 5633: 5632: 5616: 5604: 5602:, p. 353) 5592: 5580: 5547:(4): 258–260. 5524: 5503: 5488: 5477: 5465: 5450: 5435: 5426:, p. 558) 5416: 5414:, p. 434) 5404: 5392: 5388:Skilling (1951 5380: 5368: 5356: 5351:978-0060469825 5350: 5329: 5327:, p. 130) 5316: 5305: 5300:978-0070274068 5299: 5279: 5269: 5251: 5241: 5223: 5187: 5186: 5184: 5181: 5178: 5177: 5162: 5161: 5159: 5156: 5155: 5154: 5148: 5143: 5138: 5133: 5128: 5123: 5118: 5111: 5108: 5091: 5088: 5071: 5066: 5063: 5039: 5036: 5012: 5009: 4989: 4986: 4973: 4972: 4969: 4968: 4965: 4961: 4960: 4957: 4953: 4952: 4949: 4945: 4944: 4941: 4937: 4936: 4933: 4929: 4928: 4925: 4921: 4920: 4917: 4913: 4912: 4909: 4905: 4904: 4899: 4877: 4876: 4873: 4872: 4869: 4865: 4864: 4861: 4857: 4856: 4853: 4849: 4848: 4845: 4841: 4840: 4831: 4791: 4787: 4763: 4760: 4755: 4722: 4719: 4714: 4711: 4704: 4701: 4698: 4691: 4688: 4684: 4680: 4677: 4669: 4666: 4663: 4643: 4638: 4634: 4613: 4612: 4600: 4597: 4587: 4568: 4565: 4545: 4542: 4532: 4520: 4517: 4507: 4495: 4490: 4486: 4475: 4462: 4458: 4455: 4432: 4429: 4419: 4407: 4404: 4393: 4374: 4368: 4365: 4360: 4356: 4351: 4345: 4342: 4335: 4330: 4326: 4321: 4314: 4311: 4305: 4302: 4299: 4296: 4292: 4287: 4284: 4282: 4280: 4273: 4268: 4264: 4258: 4254: 4250: 4247: 4244: 4241: 4238: 4235: 4230: 4227: 4220: 4215: 4212: 4207: 4204: 4202: 4200: 4197: 4196: 4182: 4181: 4174: 4168: 4162: 4159: 4156: 4149: 4141: 4138: 4063: 4060: 4051:itself. Only 4040:direct-current 4007: 4004: 3986: 3981: 3974: 3970: 3966: 3961: 3956: 3953: 3946: 3941: 3934: 3930: 3926: 3921: 3914: 3910: 3906: 3901: 3897: 3890: 3887: 3884: 3881: 3878: 3864: 3863: 3860: 3859: 3856: 3853: 3850: 3847: 3843: 3842: 3839: 3836: 3833: 3830: 3826: 3825: 3822: 3819: 3816: 3813: 3809: 3808: 3805: 3802: 3799: 3796: 3792: 3791: 3788: 3785: 3782: 3779: 3775: 3774: 3771: 3768: 3765: 3762: 3758: 3757: 3754: 3751: 3748: 3745: 3741: 3740: 3735: 3730: 3725: 3720: 3706: 3703: 3680: 3658: 3655: 3652: 3649: 3646: 3597: 3593: 3588: 3584: 3553: 3549: 3540: 3536: 3527: 3523: 3514: 3489: 3484: 3481: 3476: 3472: 3469: 3463: 3460: 3454: 3450: 3444: 3441: 3437: 3433: 3398: 3369: 3365: 3356: 3352: 3343: 3339: 3330: 3318: 3317: 3304: 3301: 3298: 3295: 3292: 3265: 3252: 3251: 3238: 3235: 3232: 3229: 3226: 3199: 3186: 3185: 3172: 3169: 3166: 3139: 2944: 2941: 2869: 2866: 2862: 2827: 2824: 2797: 2791: 2788: 2785: 2782: 2777: 2773: 2767: 2764: 2761: 2758: 2753: 2749: 2739: 2736: 2733: 2728: 2725: 2719: 2709: 2666: 2663: 2658: 2654: 2648: 2645: 2638: 2632: 2626: 2621: 2604: 2582: 2579: 2576: 2551: 2548: 2545: 2540: 2537: 2531: 2525: 2522: 2519: 2516: 2513: 2510: 2507: 2502: 2499: 2493: 2490: 2470: 2422: 2419: 2417: 2414: 2402: 2396: 2393: 2390: 2387: 2382: 2378: 2372: 2369: 2366: 2363: 2358: 2354: 2347: 2344: 2341: 2337: 2333: 2330: 2327: 2324: 2320: 2299: 2293: 2290: 2287: 2284: 2279: 2275: 2269: 2266: 2263: 2259: 2234: 2214: 2211: 2208: 2205: 2201: 2179: 2158: 2132: 2128: 2107: 2104: 2101: 2098: 2095: 2090: 2086: 2081: 2077: 2074: 2071: 2068: 2064: 2043: 2040: 2037: 2034: 2031: 2027: 2021: 2017: 2013: 2010: 2007: 2004: 2000: 1993: 1990: 1986: 1979: 1976: 1971: 1968: 1965: 1962: 1958: 1949: 1945: 1941: 1935: 1931: 1925: 1922: 1919: 1916: 1912: 1906: 1902: 1898: 1895: 1892: 1889: 1885: 1879: 1875: 1857:Combining the 1854: 1851: 1838: 1826: 1825: 1812: 1808: 1802: 1798: 1794: 1791: 1781: 1763: 1758: 1754: 1743: 1726: 1723: 1713: 1697: 1694: 1689: 1686: 1679: 1676: 1666: 1648: 1644: 1641: 1638: 1632: 1626: 1622: 1619: 1616: 1613: 1606: 1603: 1593: 1579: 1574: 1570: 1559: 1545: 1540: 1536: 1525: 1513: 1509: 1498: 1484: 1481: 1478: 1475: 1471: 1460: 1438: 1435: 1432: 1429: 1425: 1414: 1400: 1397: 1387: 1373: 1370: 1359: 1341: 1338: 1335: 1332: 1327: 1323: 1317: 1314: 1311: 1308: 1303: 1299: 1292: 1289: 1286: 1282: 1278: 1272: 1269: 1266: 1263: 1258: 1254: 1248: 1245: 1242: 1239: 1234: 1230: 1220: 1217: 1214: 1208: 1204: 1198: 1195: 1192: 1189: 1185: 1157: 1154: 1148:100 kHz ( 1134: 1123: 1118: 1108: 1105: 1101: 1098: 1078: 1075: 1072: 1069: 1065: 1061: 1030: 1008: 996: 993: 987: 984: 975: 972: 952: 949: 946: 943: 939: 935: 923: 922: 906: 901: 897: 886: 870: 865: 861: 850: 837: 833: 826: 822: 798: 795: 785: 770: 765: 761: 750: 734: 729: 725: 714: 701: 697: 690: 686: 662: 659: 649: 637: 617: 614: 611: 608: 605: 582: 579: 569: 554: 551: 540: 521: 517: 514: 511: 508: 500: 495: 491: 488: 485: 481: 476: 473: 467: 460: 457: 451: 448: 439: 436: 417: 411:speed of light 407:phase velocity 386: 374:is called the 363: 340: 336: 332: 329: 326: 323: 320: 317: 313: 309: 301: 296: 292: 289: 273: 258: 255: 227:direct current 186: 155: 152: 69:such that the 15: 9: 6: 4: 3: 2: 5885: 5874: 5871: 5869: 5866: 5865: 5863: 5846: 5842: 5838: 5834: 5830: 5824: 5820: 5816: 5812: 5807: 5804: 5798: 5794: 5789: 5785: 5781: 5780:Terman, F. E. 5777: 5774:, McGraw-Hill 5773: 5768: 5765: 5759: 5755: 5750: 5747: 5746:0-87942-238-6 5743: 5739: 5735: 5732: 5726: 5722: 5717: 5714: 5708: 5704: 5699: 5696: 5690: 5685: 5684: 5677: 5673: 5671:0-201-02117-X 5667: 5663: 5662: 5656: 5653: 5647: 5643: 5638: 5637: 5630: 5626: 5620: 5613: 5612:Feynman (1964 5608: 5601: 5600:Jackson (1999 5596: 5589: 5584: 5570: 5566: 5562: 5558: 5554: 5550: 5546: 5542: 5538: 5531: 5529: 5513: 5507: 5499: 5492: 5486: 5481: 5475:, p. 385 5474: 5469: 5461: 5454: 5448:, p. 26) 5447: 5442: 5440: 5431: 5425: 5420: 5413: 5408: 5401: 5396: 5389: 5384: 5377: 5372: 5365: 5360: 5353: 5347: 5343: 5336: 5334: 5326: 5320: 5314: 5309: 5302: 5296: 5292: 5291: 5283: 5276: 5272: 5266: 5262: 5255: 5248: 5244: 5238: 5234: 5227: 5219: 5215: 5211: 5207: 5203: 5199: 5192: 5188: 5174: 5167: 5163: 5152: 5149: 5147: 5144: 5142: 5139: 5137: 5134: 5132: 5129: 5127: 5124: 5122: 5119: 5117: 5114: 5113: 5107: 5105: 5101: 5097: 5087: 5085: 5069: 5064: 5061: 5037: 5034: 5010: 5007: 4995: 4985: 4982: 4978: 4966: 4963: 4962: 4958: 4955: 4954: 4950: 4947: 4946: 4942: 4939: 4938: 4934: 4931: 4930: 4926: 4923: 4922: 4918: 4915: 4914: 4910: 4907: 4906: 4900: 4897: 4896: 4890: 4889: 4888: 4885: 4883: 4870: 4867: 4866: 4862: 4859: 4858: 4854: 4851: 4850: 4846: 4843: 4842: 4838: 4832: 4829: 4828: 4822: 4821: 4820: 4818: 4813: 4811: 4807: 4789: 4785: 4775: 4761: 4758: 4753: 4734: 4712: 4709: 4702: 4699: 4696: 4689: 4686: 4682: 4678: 4675: 4667: 4664: 4661: 4641: 4636: 4632: 4598: 4595: 4588: 4566: 4563: 4543: 4540: 4533: 4518: 4515: 4508: 4493: 4488: 4484: 4476: 4460: 4456: 4453: 4430: 4427: 4420: 4405: 4402: 4395: 4394: 4392: 4389: 4372: 4366: 4363: 4358: 4354: 4349: 4343: 4340: 4333: 4328: 4324: 4319: 4312: 4309: 4303: 4300: 4297: 4294: 4290: 4285: 4283: 4266: 4262: 4256: 4252: 4242: 4239: 4236: 4228: 4225: 4218: 4213: 4210: 4205: 4203: 4198: 4180:(80%Ni-20%Fe) 4179: 4175: 4173: 4169: 4167: 4163: 4160: 4157: 4155: 4151: 4150: 4146: 4137: 4135: 4129: 4126: 4122: 4118: 4113: 4110: 4108: 4104: 4099: 4095: 4093: 4089: 4084: 4081: 4076: 4071: 4069: 4059: 4056: 4054: 4050: 4045: 4041: 4036: 4034: 4029: 4025: 4024:ferromagnetic 4021: 4016: 4014: 4003: 3984: 3979: 3972: 3968: 3964: 3959: 3954: 3951: 3944: 3939: 3932: 3928: 3924: 3919: 3908: 3904: 3899: 3895: 3888: 3882: 3876: 3867: 3857: 3854: 3851: 3848: 3845: 3844: 3840: 3837: 3834: 3831: 3828: 3827: 3823: 3820: 3817: 3814: 3811: 3810: 3806: 3803: 3800: 3797: 3794: 3793: 3789: 3786: 3783: 3780: 3777: 3776: 3772: 3769: 3766: 3763: 3760: 3759: 3755: 3752: 3749: 3746: 3743: 3742: 3736: 3731: 3726: 3721: 3716: 3715: 3712: 3711: 3710: 3702: 3698: 3678: 3656: 3653: 3650: 3647: 3644: 3636: 3633: =  3632: 3628: 3625: =  3624: 3619: 3616: 3595: 3591: 3582: 3572: 3551: 3547: 3538: 3534: 3525: 3521: 3512: 3502: 3487: 3482: 3479: 3474: 3470: 3467: 3461: 3458: 3452: 3448: 3442: 3439: 3435: 3431: 3423: 3419: 3396: 3387: 3367: 3363: 3354: 3350: 3341: 3337: 3328: 3302: 3299: 3296: 3293: 3290: 3263: 3254: 3253: 3236: 3233: 3230: 3227: 3224: 3197: 3188: 3187: 3170: 3167: 3164: 3137: 3128: 3127: 3126: 3123: 3116: 3112: 3104: 3096: 3088: 3080: 3072: 3064: 3056: 3048: 3040: 3026: 3015: 3002: 2989: 2979: 2972: 2968: 2966: 2943:Coaxial cable 2940: 2936: 2933: 2929: 2923: 2920: 2908: 2897: 2892: 2888: 2886: 2867: 2864: 2860: 2849: 2845: 2841: 2837: 2833: 2823: 2821: 2817: 2813: 2808: 2795: 2786: 2783: 2775: 2771: 2762: 2759: 2751: 2747: 2737: 2734: 2731: 2726: 2723: 2717: 2697: 2694: 2690: 2686: 2681: 2656: 2652: 2636: 2630: 2619: 2599: 2594: 2580: 2577: 2574: 2565: 2549: 2546: 2543: 2538: 2535: 2529: 2523: 2517: 2514: 2511: 2505: 2500: 2497: 2491: 2488: 2468: 2452: 2451:approximately 2428: 2413: 2400: 2391: 2388: 2380: 2376: 2367: 2364: 2356: 2352: 2342: 2331: 2325: 2297: 2288: 2285: 2277: 2273: 2264: 2212: 2206: 2156: 2148: 2130: 2126: 2105: 2099: 2096: 2088: 2084: 2075: 2069: 2041: 2038: 2032: 2019: 2015: 2011: 2005: 1991: 1977: 1974: 1969: 1963: 1947: 1943: 1933: 1923: 1917: 1904: 1900: 1896: 1890: 1877: 1864: 1860: 1850: 1836: 1810: 1806: 1800: 1796: 1792: 1789: 1782: 1779: 1761: 1756: 1752: 1744: 1741: 1724: 1721: 1714: 1695: 1692: 1687: 1684: 1677: 1674: 1667: 1664: 1646: 1642: 1639: 1636: 1630: 1624: 1620: 1617: 1614: 1611: 1604: 1601: 1594: 1577: 1572: 1568: 1560: 1543: 1538: 1534: 1526: 1511: 1499: 1482: 1476: 1461: 1458: 1455:at distance, 1454: 1436: 1430: 1415: 1398: 1395: 1388: 1371: 1368: 1361: 1360: 1358: 1355: 1336: 1333: 1325: 1321: 1312: 1309: 1301: 1297: 1287: 1276: 1267: 1264: 1256: 1252: 1243: 1240: 1232: 1228: 1218: 1215: 1212: 1202: 1196: 1190: 1169: 1165: 1163: 1153: 1145: 1132: 1121: 1116: 1106: 1103: 1099: 1096: 1073: 1070: 1063: 1059: 1050: 1044: 1028: 1019: 1006: 994: 991: 985: 982: 973: 970: 947: 944: 937: 933: 920: 904: 899: 895: 887: 884: 868: 863: 859: 851: 835: 831: 824: 820: 811: 796: 793: 786: 784: 768: 763: 759: 751: 748: 732: 727: 723: 715: 699: 695: 688: 684: 675: 660: 657: 650: 635: 615: 612: 609: 606: 603: 595: 580: 577: 570: 567: 552: 549: 542: 541: 539: 536: 519: 515: 512: 509: 506: 498: 493: 489: 486: 483: 479: 474: 471: 465: 458: 455: 449: 446: 437: 434: 425: 423: 412: 408: 404: 396: 392: 381: 377: 361: 338: 334: 330: 324: 321: 318: 311: 307: 294: 290: 287: 268: 254: 252: 247: 243: 239: 235: 230: 228: 224: 220: 216: 212: 207: 205: 201: 185: 179: 173: 167: 160: 151: 149: 145: 140: 138: 134: 130: 126: 122: 118: 113: 111: 106: 104: 100: 95: 90: 88: 84: 80: 76: 75:eddy currents 72: 68: 64: 60: 56: 48: 44: 40: 33: 28: 22: 5810: 5792: 5783: 5771: 5753: 5737: 5720: 5702: 5682: 5660: 5641: 5624: 5619: 5607: 5595: 5583: 5572:. Retrieved 5544: 5540: 5516:. Retrieved 5506: 5497: 5491: 5480: 5468: 5459: 5453: 5419: 5407: 5395: 5383: 5371: 5366:, p. ?? 5359: 5341: 5325:Jordan (1968 5319: 5308: 5289: 5282: 5274: 5260: 5254: 5246: 5232: 5226: 5201: 5197: 5191: 5172: 5166: 5121:Eddy current 5096:Heinz London 5093: 4997: 4976: 4974: 4967:2.06   4959:6.52   4886: 4878: 4814: 4776: 4735: 4615: 4390: 4186: 4130: 4114: 4111: 4106: 4100: 4096: 4085: 4078:composed of 4075:transformers 4072: 4067: 4065: 4057: 4053:non-magnetic 4037: 4020:permeability 4017: 4009: 3868: 3865: 3708: 3699: 3634: 3630: 3626: 3622: 3620: 3617: 3573: 3503: 3421: 3417: 3388: 3319: 3124: 3120: 3114: 3106: 3098: 3090: 3082: 3074: 3066: 3058: 3050: 3042: 3036: 3024: 3013: 3007:= dielectric 3000: 2987: 2977: 2960: 2946: 2937: 2931: 2927: 2924: 2918: 2914: 2895: 2847: 2843: 2835: 2831: 2829: 2809: 2692: 2682: 2595: 2566: 2450: 2424: 1856: 1828: 1456: 1356: 1175: 1159: 1146: 1051: 1020: 925: 883:permittivity 810:permittivity 674:permeability 537: 426: 375: 260: 245: 233: 231: 218: 214: 208: 196: 181: 175: 169: 163: 141: 114: 107: 91: 86: 82: 58: 52: 5424:Reeve (1995 5364:Terman 1943 5204:: 519–549. 5131:Transformer 4742:10 Ω·m 4622:10 Ω·m 4584:10 S/m 4068:Litzendraht 4033:laminations 4028:micrometers 3420:per length 2992:= conductor 2885:table below 2598:F.E. Terman 1740:resistivity 1663:wave number 596:of current 566:resistivity 422:Snell's law 246:skin effect 215:skin effect 144:Horace Lamb 59:skin effect 5862:Categories 5588:Hayt (1981 5574:2020-12-22 5518:2011-11-08 5446:Chen (2004 5412:Hayt (1981 5400:Hayt (1981 5376:Hayt (1981 5183:References 5084:waveguides 4992:See also: 4901:Skin depth 4833:Skin depth 4817:micrometer 4090:often use 4062:Mitigation 2826:Inductance 2820:inductance 2421:Resistance 1853:Derivation 1156:Round wire 1047:10 Hz 395:wavelength 376:skin depth 219:skin depth 119:circuits, 99:resistance 87:skin depth 5845:114947614 5837:0197-2618 5561:1531-1309 5218:111283238 5173:magnitude 5126:Litz wire 5062:δ 4898:Frequency 4830:Conductor 4786:μ 4700:⋅ 4687:− 4679:⋅ 4662:δ 4633:μ 4567:≈ 4564:σ 4541:σ 4516:μ 4485:μ 4428:α 4403:δ 4367:σ 4355:μ 4341:≈ 4325:μ 4320:ρ 4310:≈ 4304:σ 4301:μ 4295:π 4263:μ 4253:μ 4240:π 4229:ρ 4214:α 4199:δ 4178:permalloy 4125:microwave 3913:∞ 3909:ℓ 3896:ℓ 3717:Frequency 3587:∞ 3471:⁡ 3462:π 3449:μ 3029:= current 3018:= current 2981:= overall 2868:π 2861:μ 2840:induction 2816:reactance 2735:π 2727:ρ 2696:impedance 2581:δ 2578:≫ 2550:δ 2544:π 2539:ρ 2536:ℓ 2530:≈ 2524:δ 2518:δ 2515:− 2506:π 2501:ρ 2498:ℓ 2492:≈ 2469:ρ 2416:Impedance 2149:of order 1989:∂ 1985:∂ 1940:∂ 1930:∂ 1874:∇ 1865:produces 1863:Ohm's law 1807:μ 1797:μ 1790:μ 1776:relative 1753:μ 1722:ρ 1696:μ 1693:ω 1688:ρ 1675:δ 1647:δ 1640:− 1625:ρ 1621:μ 1618:ω 1612:− 1216:π 1122:μ 1117:ε 1107:ρ 1100:≈ 1097:δ 1074:ε 1071:ρ 1029:ε 995:μ 992:ω 986:ρ 971:δ 948:ε 945:ρ 896:ε 881:relative 860:ε 832:ε 821:ε 794:ε 760:μ 745:relative 724:μ 696:μ 685:μ 658:μ 610:π 578:ω 550:ρ 516:ε 513:ω 510:ρ 490:ε 487:ω 484:ρ 459:μ 456:ω 450:ρ 435:δ 362:δ 339:δ 312:− 238:induction 200:electrons 150:in 1885. 117:microwave 110:litz wire 94:frequency 67:conductor 47:Litz wire 5782:(1943), 5569:30187468 5110:See also 4844:Aluminum 4170:Fe-Si – 4140:Examples 4013:2000 MCM 3739:(nF/km) 3117:remains. 2848:external 2693:internal 2246:must be 217:and the 125:antennas 101:. At 60 79:magnetic 4880:3  4154:ferrite 4044:welding 3855:118.074 3734:(μS/km) 3729:(mH/km) 3670:. Only 3005:  2997:  2967:below. 2844:outside 2812:complex 391:delayed 257:Formula 234:induced 5843:  5835:  5825:  5799:  5760:  5744:  5727:  5709:  5691:  5668:  5648:  5567:  5559:  5348:  5297:  5267:  5239:  5216:  4981:busbar 4871:0.634 4868:Silver 4863:0.753 4855:0.652 4852:Copper 4847:0.820 4391:where 4117:plated 4107:ribbon 4103:busbar 3858:51.57 3852:0.4675 3849:999.41 3841:51.57 3838:53.205 3835:0.4862 3832:643.14 3824:51.57 3821:29.111 3818:0.5062 3815:463.59 3807:51.57 3801:0.5807 3798:191.63 3790:51.57 3784:0.6099 3781:172.70 3773:51.57 3767:0.6125 3764:172.28 3756:51.57 3750:0.6129 3747:172.24 3724:(Ω/km) 3035:flux ( 2955:, and 2919:inside 2911:depth. 2832:inside 2640:  2427:losses 2310:Thus, 2118:where 1829:Since 1453:phasor 1357:where 1130:  1004:  628:where 538:where 403:vacuum 354:where 5841:S2CID 5565:S2CID 5214:S2CID 5158:Notes 4903:(μm) 4042:(DC) 3804:3.327 3787:0.531 3770:0.072 3753:0.000 3333:total 3089:and 3014:green 3001:white 2978:black 2685:cable 2145:is a 240:. An 154:Cause 5833:ISSN 5823:ISBN 5797:ISBN 5758:ISBN 5742:ISBN 5725:ISBN 5707:ISBN 5689:ISBN 5666:ISBN 5646:ISBN 5557:ISSN 5430:help 5346:ISBN 5295:ISBN 5265:ISBN 5237:ISBN 4860:Gold 4713:11.1 4676:2.44 4618:2.44 4580:58.5 3719:(Hz) 3654:< 3648:< 3300:< 3294:< 3234:< 3228:< 3168:< 3025:blue 2611:is: 2481:is: 2169:and 1861:and 1661:the 917:the 781:the 83:skin 21:skin 5815:doi 5549:doi 5206:doi 5202:174 5082:In 5052:is 4975:In 4738:2.2 4668:503 4344:503 4313:503 4123:to 4121:VHF 4049:arc 3683:ext 3600:ext 3556:ext 3543:shd 3530:cen 3401:ext 3372:ext 3359:shd 3346:cen 3268:shd 3202:ext 3142:cen 2988:tan 2713:int 2637:200 223:1/e 53:In 5864:: 5839:. 5831:. 5821:. 5563:. 5555:. 5545:26 5543:. 5539:. 5527:^ 5438:^ 5332:^ 5273:. 5245:. 5212:. 5200:. 5106:. 4882:μm 4839:) 4837:μm 4819:: 4703:50 4683:10 4134:5G 3615:. 3571:. 3517:DC 3468:ln 3009:, 2994:, 2951:, 2898:/8 2887:. 2593:. 2042:0. 1049:. 253:. 103:Hz 89:. 57:, 5847:. 5817:: 5748:. 5674:. 5551:: 5521:. 5432:) 5220:. 5208:: 5070:. 5065:2 5038:e 5035:1 5011:e 5008:1 4835:( 4790:r 4762:3 4759:= 4754:9 4740:× 4721:m 4718:m 4710:= 4697:1 4690:8 4665:= 4642:= 4637:r 4620:× 4599:= 4596:f 4586:) 4582:× 4544:= 4519:= 4494:= 4489:0 4461:m 4457:p 4454:N 4431:= 4406:= 4373:, 4364:f 4359:r 4350:1 4334:f 4329:r 4298:f 4291:1 4286:= 4272:) 4267:r 4257:0 4249:( 4246:) 4243:f 4237:2 4234:( 4226:2 4219:= 4211:1 4206:= 3985:b 3980:) 3973:m 3969:f 3965:f 3960:( 3955:+ 3952:1 3945:b 3940:) 3933:m 3929:f 3925:f 3920:( 3905:+ 3900:0 3889:= 3886:) 3883:f 3880:( 3877:L 3737:C 3732:G 3727:L 3722:R 3679:L 3657:c 3651:r 3645:b 3635:b 3631:r 3627:a 3623:r 3596:L 3592:= 3583:L 3552:L 3548:+ 3539:L 3535:+ 3526:L 3522:= 3513:L 3488:) 3483:a 3480:b 3475:( 3459:2 3453:0 3443:= 3440:D 3436:/ 3432:L 3422:D 3418:L 3397:L 3368:L 3364:+ 3355:L 3351:+ 3342:L 3338:= 3329:L 3303:c 3297:r 3291:b 3264:L 3237:b 3231:r 3225:a 3198:L 3171:a 3165:r 3138:L 3109:D 3101:C 3093:D 3085:C 3077:B 3069:D 3061:C 3053:B 3045:A 3038:B 2963:A 2957:c 2953:b 2949:a 2900:π 2896:μ 2865:8 2796:. 2790:) 2787:R 2784:k 2781:( 2776:1 2772:J 2766:) 2763:R 2760:k 2757:( 2752:0 2748:J 2738:R 2732:2 2724:k 2718:= 2708:Z 2665:z 2662:H 2657:/ 2653:f 2647:m 2644:m 2631:= 2625:W 2620:D 2609:f 2605:W 2602:D 2575:D 2547:D 2521:) 2512:D 2509:( 2489:R 2459:ℓ 2455:δ 2447:δ 2443:D 2439:δ 2435:δ 2431:δ 2401:. 2395:) 2392:R 2389:k 2386:( 2381:0 2377:J 2371:) 2368:r 2365:k 2362:( 2357:0 2353:J 2346:) 2343:R 2340:( 2336:J 2332:= 2329:) 2326:r 2323:( 2319:J 2298:. 2292:) 2289:R 2286:k 2283:( 2278:0 2274:J 2268:) 2265:R 2262:( 2258:J 2233:C 2213:, 2210:) 2207:R 2204:( 2200:J 2178:C 2157:0 2131:0 2127:J 2106:, 2103:) 2100:r 2097:k 2094:( 2089:0 2085:J 2080:C 2076:= 2073:) 2070:r 2067:( 2063:J 2039:= 2036:) 2033:r 2030:( 2026:J 2020:2 2016:k 2012:+ 2009:) 2006:r 2003:( 1999:J 1992:r 1978:r 1975:1 1970:+ 1967:) 1964:r 1961:( 1957:J 1948:2 1944:r 1934:2 1924:= 1921:) 1918:r 1915:( 1911:J 1905:2 1901:k 1897:+ 1894:) 1891:r 1888:( 1884:J 1878:2 1837:k 1811:0 1801:r 1793:= 1762:= 1757:r 1725:= 1685:2 1678:= 1643:j 1637:1 1631:= 1615:j 1605:= 1602:k 1578:= 1573:1 1569:J 1544:= 1539:0 1535:J 1512:= 1508:I 1483:= 1480:) 1477:R 1474:( 1470:J 1457:r 1437:= 1434:) 1431:r 1428:( 1424:J 1399:= 1396:R 1372:= 1369:r 1340:) 1337:R 1334:k 1331:( 1326:0 1322:J 1316:) 1313:r 1310:k 1307:( 1302:0 1298:J 1291:) 1288:R 1285:( 1281:J 1277:= 1271:) 1268:R 1265:k 1262:( 1257:1 1253:J 1247:) 1244:r 1241:k 1238:( 1233:0 1229:J 1219:R 1213:2 1207:I 1203:k 1197:= 1194:) 1191:r 1188:( 1184:J 1150:λ 1133:. 1104:2 1077:) 1068:( 1064:/ 1060:1 1007:. 983:2 974:= 951:) 942:( 938:/ 934:1 921:. 905:= 900:0 869:= 864:r 836:0 825:r 797:= 769:= 764:0 733:= 728:r 700:0 689:r 661:= 636:f 616:, 613:f 607:2 604:= 581:= 553:= 520:) 507:+ 499:2 494:) 480:( 475:+ 472:1 466:( 447:2 438:= 418:o 415:λ 399:π 387:S 384:J 380:e 335:/ 331:d 328:) 325:j 322:+ 319:1 316:( 308:e 300:S 295:J 291:= 288:J 278:d 274:S 271:J 263:J 189:W 183:I 177:H 171:H 165:I 23:.

Index

skin

alternating current

Induction cookers
Litz wire
electromagnetism
alternating electric current
conductor
current density
eddy currents
magnetic
frequency
resistance
Hz
litz wire
microwave
transmission lines
antennas
mains frequencies
electric power transmission
high-voltage direct current
Horace Lamb
Oliver Heaviside

electrons
counter-electromotive force
current density
1/e
direct current

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