(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

ok we did a temperature coefficient of resistance at class, we need to calculate the coefficient of resistance (a) ourselves.

known variable:

R = resistance

ln R = log of resistance

T = tempreature

a = coefficient of resistance

c = the intercept

2. Relevant equations

ln R = aT+c

i.e. R= k exp(aT), where k=exp(c) is a constant.

3. The attempt at a solution

at first I thought I could calculate a as if it is gradient, and therefore worked out the intercept (c). But since a is the coefficient of resistance it didn't make sense to me to do it this way. So I'm lost

Anyways this is my working:

gradient = delta ln R/ delta T

= (lnR_1-lnR_2/T_1-T_2) = -.912185/44

= -0.02682897

therefore intercept (c) = -.912185 - (-.02682897 * 44)

= 10.8925618

put it back to the equation

lnR = a*T+10.893

given T = 64, its correspond ln R = 4.957 (we measured these ourselves, assume correct)

so:

4.957 = a*64+10.893

-5.936=a*64

a=-5.936/64

a=-0.0927

put everything back to original equation:

ln R = -0.0927 T + 10.893

is this even correct??

thanks

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# Homework Help: Temperature coefficient of resistance

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