Question

show the variation with temperature in resistivity for alloys​

Answer 1

Answer:

The resistance increases as the temperature of a metallic conductor increase, so the resistance is directly proportional to the temperature

The resistivity of alloys =Ralloy, the resistivity of constituent metals Rmetal

Explanation:

Free electrons are scattered off imperfections and alloys have many more of them than pure metals. The higher resistivity in alloys as compared to the constituents is caused by an additional scattering mechanism of the electrons called "alloy scattering"

So, with increase in temperature, the resistance of conductor increases. But in case of insulator, there is a large energy gap between the two bands. So, if the temperature rise is high, the electrons will go to the upper band. ... So, the resistance decreases with increase in temperature in insulator.The resistivity of an alloy depends on the constituent metals and their relative concentrations. ... These tend to restrict the free movement of conduction electrons between atoms versus a pure metal. So an alloy will tend to have a higher resistivity than the pure metal constituents of the alloy.Constantan alloy

Its resistivity (4.9 x 10−7 Ω·m) is high enough to achieve suitable resistance values in even very small grids, and its temperature coefficient of resistance is fairly low. In addition, constantan is characterized by good fatigue life and relatively high elongation capability.