This question contains statement-$1$ and statement-$2$. Of the four choices given after the statements,choose the one that best describes the two statements.
statement-$1$: The temperature dependence of resistance is usually given as $R=R_{0}(1+\alpha \Delta t)$. The resistance of a wire changes from $100 \; \Omega$ to $150 \; \Omega$ when its temperature is increased from $27^{\circ} C$ to $227^{\circ} C$. This implies that $\alpha=2.5 \times 10^{-3} /^{\circ} C$.
statement-$2$: $R=R_{0}(1+\alpha \Delta t)$ is valid only when the change in the temperature $\Delta t$ is small and $\Delta R=(R-R_{0}) << R_{0}$.

• A
  Statement-$1$ is true,statement-$2$ is false.
• B
  Statement-$1$ is true,statement-$2$ is true; statement-$2$ is the correct explanation of Statement-$1$.
• C
  Statement-$1$ is true,statement-$2$ is true; statement-$2$ is not the correct explanation of Statement-$1$.
• D
  Statement-$1$ is false,statement-$2$ is true.