Question

A carbon resistor has a resistance of 500Ω.Determine its resistance at 50oC.

Answer 1

$R_t=R_0(1+\alpha t)$

For carbon $\alpha =-5\cdot10^{-4}°C^{-1}$ at $0°C$.

If $R_0=500 \Omega$ at $t=0°C$.

So, we have

$R_t=R_0(1+\alpha t)=500(1-0.0005\cdot50)=487.5 \Omega$