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COMEDK2024PhysicsCurrent Electricity

If the length of a wire is increased by 20 % by stretching it, then its resistance is increased to

Options

  1. A22 %
  2. B33 %
  3. C55 %
  4. D44 %

Correct answer

D. 44 %

Step-by-step solution

Given aligned & l₁=l, A₁=A & l₂=l (1+ 20 100 )= 6 l 5 , A₂=A^ aligned We have, aligned & A₁ l₁=A₂ l₂ & A l=A^ 6 l 5 A^ = 5 A 6 & R₂ R₁ = ₂ A₂ ₁ A₁ = l₂ l₁ A₁ A₂ = 6 l 5 l 6 5 ~A = 36 25 aligned Increase in the resistance, ( R₂ R₁ -1 ) 100= ( 36 25 -1 ) 100=44 %

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