Question

Find, in the given circuit, currents in $10\Omega$ and $100\Omega$ resistors and the value of R.

Answer 1

So potential drop across $10\Omega$ Resistor

$=20Volt$

$\Rightarrow 20=10\times i\Rightarrow i=2A$

Now,

$R_{Ab}=\frac{100\times R}{100+R}$

Now $100=i\times R_{AB}\Rightarrow 100=2\times \frac{R\times 100}{R+100}$

$\Rightarrow 50=\frac{100R}{R+100}\Rightarrow R+100=2R\Rightarrow R=100\Omega$