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BITSAT2024PhysicsCurrent ElectricityActual

A conducting wire is stretched by applying a deforming force, so that its diameter decreases to 40 % of original value. The percentage change in its resistance will be

Options

  1. A0.9 %
  2. B0.12 %
  3. C1.6 %
  4. D0.5 %

Correct answer

C. 1.6 %

Step-by-step solution

On stretching, volume of wire remains constant. So, V=A l or l= V A array ll & R= l A = V A^2 = V ^2 D^4 16 = 16 V ^2 D^4 & R R =-4 D D =-4(-0.4)=1.6 % array

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