Resistance ratings in wires?

Resistance is not a rating, it is a value. Higher resistance in a wire means, when in use with current through it, more voltage is dropped in the wire, more power is lost in the wire, and the wire will run warmer or hotter. If you have a specific example, let me know. Examples are always easier to understand than generalities. A wire can have a higher resistance because it is thinner, or made of a different material, or longer. Copper is the best material as it has the lowest resistance, with the exception of silver. edit: it really does pay to mention all the details in a question. The 50Ω and 75Ω rating on a cable is not the resistance, it is the characteristic impedance rating of the cable, and is related to the high frequency performance. Radio frequency circuits (radios, cable boxes, antennae) are designed for a characteristic impedance, usually 50 or 75Ω, and you should use the cable whose characteristic impedance matches that or you will have losses. To explain why would take a lot of time. .

Ted's answer only above this a chance be the perfect clarification so some distance... the mixed score might want to be quite decrease than double because of the inevitable variance in resistance between both fuses. As for the layout of the fuses, all of them function by technique of the nice and cozy temperature of the present passing by skill of them causing their conductors to warmth up and smash aside, causing an open circuit. It does take a particular era of time for this warmth to strengthen besides the indisputable fact that, and reason the reaction. some fuses are designed to face up to short over modern-day situations without blowing (sluggish-blow fuses), while others are quick-appearing fuses, designed to soften and open very instantly (only about right now). the right decision relies upon on the appliance. For fireplace prevention, the position all the different factors are tolerant of short over-currents beforehand they develop right into a fireplace threat (alongside with domicile wiring), and the position moderate/short ability fluctuations are common, that demands a sluggish-reacting fuse/breaker ingredient. solid state electronics (transistors, IC chips and such) are typically more beneficial gentle and consequently require quick-reacting fuses, and ideally some form of ability administration to tender/adjust/reduce currents from its ability grant. affordable workstation modems use small capacitors truly of fuses to guard your workstation from lightning. even as lightning motives a ability surge interior the phone line, the capacitor shorts out to floor more beneficial instantly than your well-known fuse. obviously, if you're like maximum persons, you replace the finished modem truly than replace only the blown capacitor... and the manufacturers want it that way. To make you purchase yet another modem... the jerks. :-)

Just to throw my two cents in and respond as far as an electrical wire standpoint. When you send power through a wire it is like the toy you see in a science store. The one with 6 steel balls hanging from strings and when you knock one against the other the last one bounces off. Same thing in a wire. The electron on one end hits another that hits another and so on. If a wire's electron chemical makeup are far apart, they have longer to travel to knock the next electron. Also, if the wire is solid or braided makes a big difference for the same reasons. The heat factor is due to friction. Say you have an 8' wide hallway and 100 people to exit. Not to big of a deal, everyone gets out. Try to do that with a 4' hallway? Everyone is pushing and bumping into each other.... friction.

Those ratings are not resistance as it is normally understood. I believe they refer to signal to ground capacitance.

Resistance is a characteristic of a conductor that numerically describes its inherent ability to oppose the flow of an electric current. Resistance is a function of the metallurgy of the conductor material, and its cross-sectional dimension. You cited the specific example of coaxial cable, and mentioned 50 ohm and 75 ohm examples. Actually, in the case of coaxial cable, the ohmic figure is not the resistance, but rather the reactance, and is a function mainly of the spacing between the inner conductor and the outer sheath. While reactance may also be viewed as a parameter that describes the inherent characteristic of the wire in opposing the flow of current, in the case of coaxial cable, it is more important to recognize that the issue is not so much the flow of current as it is the ability of the cable to transfer an electrical signal. And the important thing to know is that the ability of a coaxial cable to transfer a signal is optmized if the reactance of the cable matches the reactance of the output of the sending device, and the input of the receiving device. So, the critical point is that you want to choose a coaxial cable whose reactance is appropriate for the application.

Be sIdes learning a lot more about wire in general, you might want to get a copy of the NEC (National Electric Code). You can find it at varioous stores that deal with electrical materials, or on line. Barring super cold materials, every metal has resistance, and as billrus said, it is a value, not a rating. A one inch piece of #18 wire has less resistance than 1000 feet of #8 wire, but the #18 wire can still only carry just so much voltage and current without being destroyed. Do more study on the subject, you'll be glad that you did.

Many local electrical codes contain regulations about maximum allowable volt drop. This is where the resistance of the wire is important as it is part of the calculation to determine volt drop. Of course the longer the wire, the more resistance so longer runs may require going up a size or two in wire so not to have too much volt drop.

high resistance rating mean the wire has greater resistance it mean it will attenuates the motion of electtron more than the wire which has less resitance. more current flow throw the lesser resitive wire.

the type of conductor, cross sectional area and length determines the resistance in a conductor.