Question

The temperature coefficient of resistance of a wire is $0.00125$ per ${}^{o}C$. At $300$K, its resistance is $1\Omega$. This resistance of the wire will be $2\Omega$ at.

• A. $1154$K
• B. $1100$K
• C. $1400$K
• D. $1127$K

Answer 1

The correct option is D $1127$K

From the question, we know that

$\frac{{\rho }_1}{{\rho }_2}=\frac{(1+\alpha t_1)}{(1+\alpha t_2)}\Rightarrow \frac{1}{2}=\frac{(1+0.00125\times 27)}{(1+0.00125\times t)}$

$\Rightarrow t={854}^{o}C\Rightarrow T=1127K$