Start Free Mock LoginAlready registered? Login here

Physics - Current Electricity Question with Solution | TestHub

PhysicsCurrent ElectricityMicroscopicEasy2 minQB

PhysicsEasysingle choice

A uniform wire of length $l$ and radius $r$ has a resistance of $100Ω$ . It is recast into a wire of radius $\frac{r}{2}$ . The resistance of new wire will be-

Options:

Answer:

Solution:

$R = ρ \frac{l}{A}$

$A l = V$

$R = \frac{ρ V}{A ^{2}}$

$ρ \to$ constant

$V \to$ constant

$R \propto \frac{1}{A ^{2}} \propto$ $\frac{1}{( r ^{2} ) ^{2}}$

$R \propto \frac{1}{r ^{4}}$

$R_{2} = 16 R_{1} = 1600Ω$

Stream:JEESubject:PhysicsTopic:Current ElectricitySubtopic:Microscopic

⏱ 2mℹ️ Source: QB

Doubts & Discussion

Loading discussions...