Eduprobe
Question:
Statement 1: The temperature dependence of resistance is usually given as R = R₀(1+αΔt). The resistance of a wire changes from 100Ω to 150Ω when its temperature is increased from 27°C to 227°C. This implies that α = 2.5 × 10⁻³/°C. Statement 2: R = R₀(1+αΔt) is valid only when the change in the temperature ΔT is small and ΔR = (R-R₀) << R₀.
Statement 1 is True, Statement 2 is False.
Statement 1 is True, Statement 2 is True; Statement 2 is a correct explanation for Statement 1.
Statement 1 is True, Statement 2 is True; Statement 2 is not the correct explanation for Statement 1.
Statement 1 is False, Statement 2 is True.
Solution:
Statement 2 is correct. The statement R = R₀(1+αΔt) is valid only for small ΔT. For a large change in temperature, the linear approximation breaks down. Thus, for ΔT = 200°C, the calculation in Statement 1, which assumes a linear relationship, is not valid.