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JEE Main 2022 (28 Jun, Shift 2) · Ohm's Law, Resistivity & Temperature

Ohm's Law, Resistivity & Temperature question from JEE Main 2022 (28 Jun, Shift 2)

Q29JEE Main 2022 · 28 JUN · SHIFT 2Easy

Ohm's Law, Resistivity & Temperature

Resistance of the wire is measured as 2 Ω\Omega and 3 Ω\Omega at 10∘^\circC and 30∘^\circC respectively. Temperature co- efficient of resistance of the material of the wire is:

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Answer: (a)

  1. Use Rt=R0(1+αt)R_t = R_0(1 + \alpha t) with 0∘C0^\circ\text{C} as reference.
  2. 32=1+30α1+10α⇒3+30α=2+60α\dfrac{3}{2} = \dfrac{1 + 30\alpha}{1 + 10\alpha} \Rightarrow 3 + 30\alpha = 2 + 60\alpha
  3. α=130≈0.033 ∘C−1\alpha = \dfrac{1}{30} \approx 0.033\ ^\circ\text{C}^{-1}
  4. So the answer is (a) 0.033 ∘C−10.033\ ^\circ\text{C}^{-1}.
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