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JEE Main202116 Mar 2021Morning ShiftPhysicsCurrent ElectricityActual

A conducting wire of length l , area of crosssection A and electric resistivity ρ is connected between the terminals of a battery. A potential difference V is developed between its ends, causing an electric current. If the length of the wire of the same material is doubled and the area of cross-section is halved, the resultant current would be___

Options

  1. A1 4 V A ρ l
  2. B3 4 V A ρ l
  3. C1 4 ρ l V A
  4. D4 V A ρ l

Correct answer

A. 1 4 V A ρ l

Step-by-step solution

As per the question Resistance = ρ 2 l A / 2 = 4 ρ l   A ⇒ Current = V R = V A 4 ρ l

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