Physics - Current Electricity Question with Solution | TestHub

PhysicsCurrent ElectricityEquivalent ResistanceEasy2 minPYQ_2020

PhysicsEasysingle choice

An electric current is passed through a circuit containing two wires of the same material, connected in parallel. If the lengths and radii of the wires are in the ratio of $4 / 3$ and $2 / 3$ , then the ratio of the currents passing through the wire will be

Options:

Answer:

Solution:

$V = I_{1} R_{1} = I_{1} \frac{ρ ℓ_{1}}{π r_{1}^{2}}$

$V = I_{2} R_{2} = I_{2} \frac{ρ ℓ_{1}}{π r_{2}^{2}}$

$\Rightarrow I_{1} R_{1} = I_{2} R_{2}$

$\Rightarrow \frac{I_{1}}{I_{2}} = \frac{R_{2}}{R_{1}} = \frac{ρ ℓ_{2}}{π r_{2}^{2}} \times \frac{π r_{1}^{2}}{ρ ℓ_{1}} = (\frac{ℓ_{2}}{ℓ_{1}}) {(\frac{r_{1}}{r_{2}})}^{2} = \frac{3}{4} \times {(\frac{2}{3})}^{2} = \frac{1}{3}$

Stream:NTA_ABHYAS_NEETSubject:PhysicsTopic:Current ElectricitySubtopic:Equivalent Resistance

⏱ 2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...