Question
Find the effective resistance of the combination.

Answer

$\text{R}_1=4\Omega$

$\text{R}_2=8\Omega$

Potential sifference = V

$\text{I}_1=\frac{\text{V}_1}{\text{R}_1}=\frac{\text{V}}{4\Omega}$

$\text{I}_2=\frac{\text{V}}{\text{R}_2}=\frac{\text{V}}{8\Omega}$

$\frac{\text{I}_1}{\text{I}_2}=\frac{\text{V}}{\text{V}}=\frac{4\Omega}{8\Omega}$

$\Rightarrow\frac{\text{I}_1}{\text{I}_2}= \frac{8}{4}$

$\Rightarrow\frac{\text{I}_1}{\text{I}_2}= \frac{2}{1}$

$\therefore \text{I}_1:\text{I}_?=2:\text{I}$

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