Q 12-03-094JEE MainJEE Main 2024 (8 Apr, Shift 1)Easy
Resistance of a wire at $0\,^\circ\text{C}$, $100\,^\circ\text{C}$ and $t\,^\circ\text{C}$ is found to be $10\ \Omega$, $10.2\ \Omega$ and $10.95\ \Omega$ respectively. The temperature $t$ in Kelvin scale is ______.
Numerical value type. Enter your answer.
Answer: 748
With $R_t = R_0(1 + \alpha t)$:
$$10.2 = 10(1 + 100\alpha) \;\Rightarrow\; \alpha = 2\times10^{-4}\ ^\circ\text{C}^{-1}$$
$$10.95 = 10(1 + \alpha t) \;\Rightarrow\; t = \frac{0.095}{2\times10^{-4}} = 475\,^\circ\text{C}$$
In kelvin: $475 + 273 = 748\ \text{K}$.
Solution by Sreeraj P, M.Sc Physics