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JEE Main 2021 (26 Feb, Shift 2) · Ohm's Law, Resistivity & Temperature

Ohm's Law, Resistivity & Temperature question from JEE Main 2021 (26 Feb, Shift 2)

Q35JEE Main 2021 · 26 FEB · SHIFT 2Medium

Ohm's Law, Resistivity & Temperature

A wire of 1Ω\Omega has a length of 1 m. It is stretched till its length increases by 25%. The percentage change in resistance to the nearest integer is:

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Answer: (d)

  1. Volume constant, so R∝l2R \propto l^2.
  2. R′/R=(1.25)2=1.5625R'/R = (1.25)^2 = 1.5625
  3. Increase ≈56%\approx 56\%. The answer is (d).
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