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Current Electricity question

2024 · 9 Apr · Shift 2 · Q87
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Current Electricity question

2024 · 9 Apr · Shift 2 · Q87

JEE MainPhysicsCurrent ElectricityNumerical+4 / −1
At room temperature (27∘C)(27^{\circ} \mathrm{C})(27∘C), the resistance of a heating element is 50Ω50 \Omega50Ω. The temperature coefficient of the material is 2.4×10−4∘C−12.4 \times 10^{-4}{ }^{\circ} \mathrm{C}^{-1}2.4×10−4∘C−1. The temperature of the element, when its resistance is 62Ω62 \Omega62Ω, is ‾\underline{\hspace{2cm}}​∘C{ }^{\circ} \mathrm{C}∘C.
Numerical answer
View written solutionFree

Correct answer: 1027

  1. Given data

    • Initial temperature: T0=27∘CT_0 = 27^\circ\mathrm{C}T0​=27∘C
    • Resistance at 27∘C27^\circ\mathrm{C}27∘C: R0=50 ΩR_0 = 50\,\OmegaR0​=50Ω
    • Temperature coefficient: α=2.4×10−4 ∘C−1\alpha = 2.4 \times 10^{-4}\,^\circ\mathrm{C}^{-1}α=2.4×10−4∘C−1
    • Final resistance: R=62 ΩR = 62\,\OmegaR=62Ω
  2. Use the linear relation of resistance with temperature

    R=R0[1+α(T−T0)]R = R_0\left[1 + \alpha (T - T_0)\right]R=R0​[1+α(T−T0​)]

    Substitute the values:

    62=50[1+2.4×10−4(T−27)]62 = 50\left[1 + 2.4 \times 10^{-4}(T - 27)\right]62=50[1+2.4×10−4(T−27)]

  3. Simplify the equation

    Divide both sides by 505050:

    6250=1+2.4×10−4(T−27)\frac{62}{50} = 1 + 2.4 \times 10^{-4}(T - 27)5062​=1+2.4×10−4(T−27)

    1.24=1+2.4×10−4(T−27)1.24 = 1 + 2.4 \times 10^{-4}(T - 27)1.24=1+2.4×10−4(T−27)

    0.24=2.4×10−4(T−27)0.24 = 2.4 \times 10^{-4}(T - 27)0.24=2.4×10−4(T−27)

  4. Solve for TTT

    T−27=0.242.4×10−4T - 27 = \frac{0.24}{2.4 \times 10^{-4}}T−27=2.4×10−40.24​

    T−27=1000T - 27 = 1000T−27=1000

    T=1027∘CT = 1027^\circ\mathrm{C}T=1027∘C

  5. Final answer

    1027\boxed{1027}1027​

  6. Comparison with stored answer

    Stored correct answer = 102710271027

    This matches the derived answer.

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