Answer to Question #113554 in Electric Circuits for Peter

Question

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

Answer 1

Assume that the carbon resistor has a resistance of 500Ω at $T_0 = 0\degree C$ and the temperature coefficient of resistance for carbon is $\alpha = -0.0048 \Omega/\degree C$ . Then, according to the following formula:

$R(T) = R(T_0)(1-\alpha (T-T_0))$

the resistance at $T = 50\degree C$ will be:

$R(50\degree C) = 500\Omega(1--0.0048 \Omega/\degree C(50\degree C-0\degree C)) = 380 \Omega$ .

Answer. 380 Ohms.