A silver wire has a resistance of $2.1 \Omega$ at $27.5^{\circ}C$ and a resistance of $2.7\Omega$ at $100^{\circ}$. Determine the temperature coefficient of resistivity of silver.

Question

$\begin{array}{1 1} 0.0039^{\circ}C^{-1} \\ 0.0039^{\circ}C^{-1}\\ 0.59^{\circ}C^{-1} \\ 0.0639^{\circ}C^{-1} \end{array} $