Temperature coefficient of resistance

Thread Starter


Joined Aug 19, 2011
The formula for temperature coefficient of resistance is
\(\alpha\) = ΔR/R0 ΔT
where R is R - R0, where R0 is the resistance at reference temperature usually at 0°C or 20°C.
ΔT is T - T0, again T is 0° or 20°C
when written explicitly we get
\(\alpha\) = (R - R0)/R0 (T - T0)
But while measuring temperature coefficient of resistance of the material of the coil, in metre bridge experiment,
we use the relation \(\alpha\) = R2 - R1/(R1t2 -R2t1).
How R1 and R2 comes in this relation, whereas in the original formula there is only R0.



Joined Oct 2, 2009
It appears that you are using equations from two different sources.
Just substitute R = R2, R0 = R1. Also T = t2, T0 = t1.