Physics - Current Electricity Question with Solution | TestHub

PhysicsCurrent ElectricityEquivalent ResistanceEasy2 minPYQ_2020

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

Options:

Answer:

Solution:

We know that, $R = \frac{ρ l}{A}$

Or $R = \frac{ρ l^{2}}{V o l u m e} \Rightarrow R \propto l^{2}$

According to question $l_{2} = n l_{1}$

$\frac{R_{2}}{R_{1}} = \frac{n^{2} l_{1}^{2}}{l_{1}^{2}}$ or, $\frac{R_{2}}{R_{1}} = n^{2} \Rightarrow R_{2} = n^{2} R_{1}$

as $R_{1} = R$

New resistance $(R_{2}) = n^{2} R$

Stream:NTA_ABHYAS_NEETSubject:PhysicsTopic:Current ElectricitySubtopic:Equivalent Resistance

⏱ 2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...