Physics - Current Electricity Question with Solution | TestHub

Power$=\frac{V^2}{R}$

$150=\frac{V^2}{R_{\text{net}}}$

$=\frac{{\text{15}}^2}{R_{\text{net}}}$

$\frac{1}{R_{\text{net}}}=\frac{1}{R}+\frac{1}{2}$

$\therefore R_{\text{net}}=\frac{2R}{R+2}$

$\therefore \text{150 =}\frac{{\text{15}}^2\left(R+2\right)}{2R}$

$\therefore R=6 \mathrm{\Omega }$