Question about resitivity and and resistance?

Question

a coil of wire has a resistance of 38.0 at 25 degrees celsius and 43.0 at 55 degrees celsius. What is the temperature coefficient of resitivity?

Answer 1

The formula for resistance vs temperature is

R(T1) = R(T0)*(1 + a*∆T)

where a is the temp coefficient of resistivity

In your problem R(T1) = 43.0, R(T0) = 38.0 and ∆T = 17º

43 = 38*(1 + 17*a)

43/38 = 1 + 17*a

a = [(43/38) - 1]/17

a = 0.0077 ohm/ºC

Answer 2

temperature coefficient of resitivity = ((43-38) / 38) / (55 - 25)

temperature coefficient of resitivity = .004385764

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