Question

A metallic wire has a resistance of 30Ω at 20° C and 30.16Ω at 40° C. Calculate
the temperature coefficient of resistance

Answer 1

Explanation:

its temperature coefficient will be 2.3x10⁸ ohm

Answer 2

A metallic wire has a resistance of 30Ω at 20° C and 30.16Ω at 40° C. Calculate the temperature coefficient of resistance

using formula, $R=R_0(1+\alpha\Delta T)$

where, $R_0$ is the resistance at initial temperature, R is the resistance at final temperature and α is coefficient of resistance and ∆T is the change in temperature.

here, $R_0$ = 30 Ω, R = 30.16 Ω

∆T = 40°C - 20°C = 20°C

so, 30.16 = 30(1 + α × 20)

⇒30.16 = 30 + 30 × α × 20

⇒0.16 = 600 α

⇒α = 2.667 × 10^-4 /°C