Physics - Current Electricity Question with Solution | TestHub

Ans (A,B,C,D)$\frac{1}{20}=\frac{1}{20+R}+\frac{1}{25}\therefore R=80\Omega$ Bridge is balanced. $\therefore$ No current flows through the middle branch.$P_R=I^{2}R=I^2\times 80$ $P_S=(4I{)}^2\times 5=I^2\times 80$ $P_{\text{upper }20}=I^2\times 20=20I^2$ (upper line) $;P_{\text{lower }20}=(4I{)}^2\times 20=320I^2=16P_{\text{upper }20}$ (lower line)