Question

A metallic wire has a resistance of 3.0 Ω at 0°C and 4.8 Ω at 150°C. Find the temperature coefficient of resistance of its material.

Answer 1

Here, R₀ = 30 Ω , R_t = 4.8 Ω , t = 150° C , α = ?, where α is the temperature coefficient of resistance.

We know that 

R_t = R (1 + αt)

α = `("R"_"t" - "R"_0)/("R"_0 xx "t")`

`= (4.8 - 3.0)/(3xx150)`

`= 1.8/(3xx150)`

= 4 × 10^-3° C^-1