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PhysicsCurrent ElectricityEquivalent ResistanceEasy2 minPYQ_2018

PhysicsEasysingle choice

The resistance of a wire is 'R' ohm. If it is melted and stretched to 'n' times its original length, its new resistance will be

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Answer:

Solution:

We know that, $R = \frac{ρ ℓ}{A}$ or $R = \frac{ρ ℓ ^{2}}{Volume} \Rightarrow R \propto ℓ^{2}$ According to question $ℓ_{2} = n ℓ_{1}$ $\frac{R _{2}}{R _{1}} = \frac{n ^{2} l _{1}^{2}}{l _{1}^{2}}$ or, $\frac{R _{2}}{R _{1}} = n^{2} \Rightarrow R_{2} = n^{2} R_{1}$

Stream:VITEEESubject:PhysicsTopic:Current ElectricitySubtopic:Equivalent Resistance

⏱ 2mℹ️ Source: PYQ_2018

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