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JEE Main202225 Jun 2022Evening ShiftPhysicsCurrent ElectricityActual

The length of a given cylindrical wire is increased to double of its original length. The percentage increase in the resistance of the wire will be _____ %

Correct answer

0

Step-by-step solution

As volume is constant, so, length doubled and area reduces to half. Resistance of a wire is given by R = ρ l A , where, ρ is resistivity of a material. Here, R 1 = ρ l A and R 2 = ρ 2 l A 2 = 4 R So percentage increase in the resistance will be = 4 R - R R × 100 % = 300 %

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