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 0.4 0.6 0.8 1.0 2.0 |
3.94 7.87 11.8 15.7 19.7 39.4 |
3.0 4.0 5.0 6.0 7.0 8.0 |
59.2 78.8 98.6 118.5 138.2 158.0 |
Solution


Ohm's law is valid to high accuracy because, the ratio of voltage and current for different readings is same. This implies, the resistivity of alloy is nearly independent of temperature.