Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [conductivity]

Electrical conductivity or specific conductance is the reciprocal of electrical resistivity

Electrical conductivity or specific conductance is the reciprocal of electrical resistivity, and measures a material's ability to conduct an electric current. It is commonly represented by the Greek letter σ (sigma), but κ (kappa) (especially in electrical engineering) or γ (gamma) are also occasionally used. Its SI unit is siemens per metre (S/m) and CGSE unit is reciprocal second (s−1).

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I've become an electrical conductor for my headphones... but how?

So I have a pair of Bose noise-cancellation headphones that I plug into my keyboard every night to charge them (via my keyboard's USB port). My keyboard happens to be a metallic Apple keyboard. You will see why this may be important to note…
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Why is gold preferred over silver for bond wire?

Silver is a better conductor than gold and in Integrated Circuit package where exposure to air should not be a concern Gold is used. Any particular advantage of using Gold over Silver?
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Why is current rating for multicore cable lower than single core with the same cross section?

As per this resource, a single core 10 AWG (5.3 mm2) copper cable is rated for up to 52 amps, while the same cross section cable of 43 cores and more is only allowed to carry up to 15 amps. Why is that? Why do multiple cores make it more dangerous…
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Freely rotating part that conducts electricity to fixed part - does this exist?

Planning a design that has a 12V voltage source connected to a physical part that rotates. I need to conduct electricity from the rotating part to a fixed part which is connected (electrically isolated) to free-standing structure like a pole or a…
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Is there any difference between transferring DC over one 36 mm² wire or six 6 mm² wires?

I am designing an off-grid DIY solar power site where the distance between the solar panels and inverter is going to be several dozen meters, so I would prefer to put a thicker wire to minimize losses. Though it seems pretty obvious that, in terms…
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Gold coated multimeter test probes

I found around a couple of damaged "gold coated" probes, after checking the inner wire it happens to be made of cooper, my questions here are simple 1) Why coat the tips if the rest of the probe is just copper? 2) In order to decrease the total…
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How is clearance affected by altitude (air pressure)?

Let's say you have a high-voltage circuit (or any voltage really) and you want to provide appropriate clearance distance for the PCB, connector pins, etc. (Above image from link) There are standards for choosing the correct distances. Some of them…
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Low electrical resistance, high thermal resistance conductors

I was thinking about diamonds, and how they're excellent thermal conductors and yet at the same time very good electrical insulators. Does the opposite of diamond exist, i.e. are there commonly available, inert (as in, safe to use/handle) conductors…
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What is the ampacity of 14 gauge silver wire?

There is no information I can find (charts/specifications) that gives the ampacity for single core silver wire. But I know this can be calculated, I've found this property list for silver from a [metals supplier][1] Thermal Conductivity: 428 W/m *…
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Which is a better conductor, a very thick rubber wire or a very thin copper wire?

I read somewhere that very thick wires are generally better conductors than very thin ones. Is this true? If yes, then would a very thick rubber wire be a better conductor than a very thin copper wire? Edit: By rubber wire, I mean a wire made…
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Conductivity sensor AC frequency

I'm trying to figure out how to determine what frequency an electrodeless conductivity sensor needs for accurate measurement. An inductive sensor consists of two wire-wound metal toroids encased in a corrosion-resistant plastic body. One toroid is…
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Why don't we get electrocuted when touching a pot sitting on an induction cooker

As the title says, why does that not happen. As far as my understanding goes, an induction cooker is a coil of conductive wire through which AC is pumped. This generates an oscillating magnetic field around the coil, which in turn generates a DC…
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Why are the dimensions of a floating gate layer in a MOSFET so thick?

For a floating gate MOSFET, in order to make the control gate work you have to(generally speaking) make the oxide layer thin(~100 Angstroms) as well as the ONO(Oxygen nitride, acts as an insulator) layer(~200 Angstroms). However, making it too thin…
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Does a conductor that is heavily negatively charged affect the number of free electrons or conductivity?

If a conductor is charged with several megavolts of static electricity, does it have a larger number of free electrons? If so, wouldn't they render the conductor more conductive? To truly test the conductivity, a generator that was charged to the…
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How good of a conductor is laser-induced graphene from Kapton tape (polyimide)?

I had intentions of making a DC electromagnet using laser-induced graphene (LIG), where the graphene will be used as a flexible electromagnetic coil. Something like those 24V electromagnets you can find online. But I had a concerns on the quality of…
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