For a cylinder we know R=ρL/A, and so, if L and A do not change greatly with temperature, R will have the same temperature dependence as ρ. (Examination of the coefficie...For a cylinder we know R=ρL/A, and so, if L and A do not change greatly with temperature, R will have the same temperature dependence as ρ. (Examination of the coefficients of linear expansion shows them to be about two orders of magnitude less than typical temperature coefficients of resistivity, and so the effect of temperature on L and A is about two orders of magnitude less than on ρ.) Thus, \[R = R_{0} \left( 1 + \alpha \Delta T \right) \label{…
The resistance of an object depends on its shape and the material of which it is composed. For a given shape, the resistance depends on the material of which the object is composed. Different material...The resistance of an object depends on its shape and the material of which it is composed. For a given shape, the resistance depends on the material of which the object is composed. Different materials offer different resistance to the flow of charge. We define the resistivity ρ of a substance so that the resistance R of an object is directly proportional to ρ.
