Answer
$9.3\%$
Work Step by Step
We know that
$\frac{R-R_0}{R_0}=\alpha ∆T$
For gold we have
$\frac{R-R_0}{R_0}×100=7\%$
$\alpha_G ∆T×100=7\% \hspace{2cm}(i)$
let $x$ be increase in percentage for tungsten. Therefore for Tungsten we have
$\frac{R-R_0}{R_0}×100=x$
$\alpha_T ∆T×100=x \hspace{2cm}(ii)$
Dividing $(ii)$ by $(i)$
$\frac{x}{7\%}=\frac{\alpha_T}{\alpha_G}$
$\implies x = \frac{0.0045(C^o)^-1}
{0.0034(C^o)^-1}×7\%$
$\implies x =9.3\%$
