# Temperature coefficient of resistance

Discussion in 'Physics' started by logearav, Jan 24, 2012.

1. ### logearav Thread Starter Member

Aug 19, 2011
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0
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.

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2. ### Kermit2 AAC Fanatic!

Feb 5, 2010
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There is no difference other than the choice of variable names.

3. ### MrChips Moderator

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