The goal of this lab is to measure the temperature coefficient of resistivity a for a copper resistor.
If you make a graph with
Recall the manner in which resistance changes with temperature:
R = Ro * [ 1 + a*(T-To) ]We can write this as
R = Ro + (Ro*a)*(T-To)
When you make a graph of resistance R versus temperature change T-To, you are graphing this equation.
First, determine the value of the resistance at reference temperature Ro by looking at the y-intercept of your graph. Second, measure the slope of your graph, which is Ro*a. Finally, divide
slope Ro*a ------- = ------ = a Ro Roto find the value for temperature coefficient of resistivity a.
Compare your value to that for copper -- look in reference materials in the library or on the Internet to find it.
Copyright © Michael Richmond. This work is licensed under a Creative Commons License.