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dymand68
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Homework Statement
A 1 mile long copper wire has a resistance of 68 ohms. What will be its new resistance when doubling it over and using it as "one" wire
Homework Equations
?R=V/current
OK. More generally, how does resistance depend on length and cross-sectional area?dymand68 said:I know that when it is cut in half R=34 ohms
No. Read this: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/resis.html#c2"dymand68 said:inverse square rule?
That's right. As that site explains, the resistance is inversely proportional to the cross-sectional area (which gives one factor 1/2) and directly proportional to the length (which gives a second factor of 1/2).dymand68 said:the correct answer is 17 ohms...double width, 1/2 length =1/4 resistance?
Doubling the resistance of a 1 mile copper wire means increasing its resistance by a factor of two. This means that it will require twice as much voltage to produce the same amount of current through the wire.
Resistance is measured in ohms, which is a unit of electrical resistance. In a copper wire, resistance is determined by the length, cross-sectional area, and temperature of the wire.
There are several reasons why one may want to double the resistance of a copper wire. One reason could be to increase the voltage drop in a circuit, which can be useful in certain applications. Another reason could be to reduce the amount of current flowing through the wire, which can help prevent overheating and damage to the wire.
Yes, the resistance of a copper wire can be doubled without changing its length or temperature by altering the wire's cross-sectional area. This can be done by either doubling the thickness of the wire or by using a wire with a different gauge.
To double the resistance of a 1 mile copper wire, one can either double the thickness of the wire or use a wire with a larger gauge. These methods will increase the cross-sectional area of the wire, resulting in a higher resistance. It is important to note that doubling the resistance will also affect the wire's electrical conductivity and heat dissipation capabilities.