Question

A student carried out an experiment to verify the vibration of current through an unnamed material through the p.d across it ends. He obtained the following results
Pd/v 0.50 1.00 2.00 3.00 4.00
Current/A 0.07 1.10 0.14 0.17 0.20
Questions
a) Plot a graph of p.d(vertical axis) against current (horizontal axis)
b) Use the graph to find the p.d across the material when the current is 0.81Amperes and hence determine the resistance of the material.

Answer 1

<img src="../../..//assignments/uploaded_files/static/82/ae/82aedd28bd0bcb83bc88a3c6670c4fbf.jpg" title="" alt="">
Are you sure that the data is correct?
As we can see, the material doesn't have a unique resistance at I = 0.81 A since there are two values of p.d observed. Thus the resistance is R1 = U1/I = 0.75/0.81 = 0.93 Ohm, and R2 = 1.35/0.81 = 1.67 Ohm.