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Question: Please give me some information about strong and weak resistant substances. 


We assume that we are talking about electrical resistance here. Frictional resistance to the passage of the electrical current generates heat. The more resistance the electrons meet in being pushed along, the more heat is produced.

Here's a simple example: Think of an electric toaster. It gets red hot when it's turned on, but the chord that leads to it doesn't get hot. The same amount of current goes through both the toaster and the chord. The toaster gets hot because its wires are made of high-resistance nichrome, while the chord is made of low-resistance copper wires.

The heat produced in the wire depends on its resistance.

Here is a list, in order, of the resitivities, lowest to highest of some common materials:

Silver, Copper, Aluminium, Tungsten, Brass, Iron, Manganin (made up of Copper, Manganese and Nickel), Constantan (also known as Eureka and made up of Copper and Nickel), Mercury, Nichrome. You could also include Carbon (graphite) which has a resitivity that could fit from just below Manganin to well above the resistivity of Nichrome.

There is a table at: http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/rstiv.html#c1 which has some more information and includes resitivities that could also help. 



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