Question

what is the temperature coefficient of resistance of a piece of wire having a resistance of 12. 85 ohm at 30 degrees celsius and 6.85 ohm at 0 degrees celcius. what will be its resistance at 50 degrees celsius.

Answer 1

$\rho=\rho_0(1+\alpha t)$

$12.85=\rho_0(1+\alpha \cdot30)$

$6.85=\rho_0(1+\alpha \cdot0)\to\rho_0=6.85\ (\Omega)$ . So, we have

$\alpha=(12.85/6.85-1)/30=0.0292\ (1/°C)$ . Answer

$\rho_{50}=6.85(1+0.0292\cdot50)=16.85\ (\Omega)$ . Answer