Resistance in a wire coursework

It should be noted that it is being presumed that the current is uniform across the cross-section of the wire, which is true only for Direct Current. For Alternating Current there is the phenomenon of " skin effect " in which the current density is maximum at the maximum radius of the wire and drops for smaller radii within the wire. At radio frequencies, this becomes a major factor in design because the outer part of a wire or cable carries most of the current. The inverse of resistivity is called conductivity. There are contexts where the use of conductivity is more convenient.

The repeated heating up and cooling down resistance wires are subject to during use imparts thermal stresses into the wire.  Whilst the alloy combinations have been developed over many years, and ensuring they have low temperature coefficients of linear expansion has been a key design influence, minimising these stresses will improve longevity.  In cases where it is difficult to replace the heating elements, in underfloor heating cables for instance, bunching or stranding the conductors will help.  Scott Precision wire stranded and bunched conductors are subject to the same inspection regime as solid wires, so whatever the format, the conductor will exhibit the same consistency.

The first table in combination with the second table offer a good start for selecting a wire gauge for data exchange.
As indicated 24 AWG is one of the standard wire sizes used to transfer data. This link provides a graph of 24 gauge twisted pair wire;
24AWG Frequency vs Attenuation in dB/meters.
So the table provide DC resistance and the link provides AC resistance [for 24 gauge wire].
Which leads to the two reasons to select the correct gauge wire; resistance or Wire Current carrying capacities .
Data or signaling use resistance per gauge, while power lines use Current carrying ability.
Speaker wire is normally around 16AWG [16-Gauge], also 18-gauge and 14-gauge are common.

Resistance in a wire coursework

resistance in a wire coursework


resistance in a wire courseworkresistance in a wire courseworkresistance in a wire courseworkresistance in a wire coursework