Headings Mains Electricity Search Questions 
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The Resistance of Wires - Thickness.
The resistance of a wire
depends on its thickness.
The thinner the wire, the higher its
resistance.
You must use thick wire to carry a
large current,
or the wire will get too hot and melt.
The relationship between
resistance and thickness is not straightforward,
halving the thickness does not
double the resistance
(compare this with the relationship to length).
It is the cross-sectional area of the
wire, not its thickness,
which directly affects its
resistance.
The cross-sectional area is what you get
if you cut straight through the
wire,
at right angles to its length, and look at the cut surface.
If the wire is round (most wires are),
then the cross-section is a
flat circle and the area is pr2.
Doubling the area will halve the
resistance.
Headings Mains Electricity Search Questions
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