Question

What conclusion can you draw from the following observations on a resistor made of alloy manganin?

Current A	Voltage V	Current A	Voltage V
0.2	3.94	3.0	59.2
0.4	7.87	4.0	78.8
0.6	11.8	5.0	98.6
0.8	15.7	6.0	118.5
1.0	19.7	7.0	138.2
2.0	39.4	8.0	158.0

Answer 1

It can be seen that for all the observations, the ratio of V to I is constant to fairly good accuracy i.e. ohm’s law is obeyed accurately. Hence, the resistivity of alloy manganin is nearly independent of temperature.