If the resistance of a conductor is 5 Ω at 50ºC and 7Ω

If the resistance of a conductor is 5 Ω at 50ºC and 7Ω at 100ºC, then the mean temperature coefficient of resistance (of the material) is

As we know that resistance varies with temperature as
R = R₀ [1 + αt]
Ist Case : 5 = R₀ [1 + α(50)] ....(I)
IInd Case : 7 = R₀ [1 + α(100)] .....(II)

Divided (I) by (II),	5	=	1 + 50 α
	7		1 + 100 α

5 + 500α = 7 + 350α

150α = 2 ⇒ α -	2	- 0.001 /°C
	150