خطا
در مدار (الف): $I=\frac{\varepsilon }{R+r}=\frac{12}{6+3+1}=1/2=\frac{6}{5}A$ $P=R{{I}^{2}}=6\times {{(\frac{6}{5})}^{2}}$ در شكل (ب): ${R}'=\frac{6\times 3}{6+3}=2\Omega $ ${I}'=\frac{\varepsilon }{{R}'+r}=\frac{12}{2+1+0}=4A$ ${V}'={R}'{I}'=2\times 4=8V$ ${I}''=\frac{{{V}'}}{R}=\frac{8}{6}=\frac{4}{3}A$ ${P}'=R{{{I}''}^{2}}=6\times {{(\frac{4}{3})}^{2}}$ $\frac{P}{P}=\frac{6\times (\frac{36}{25})}{6\times (\frac{16}{9})}=\frac{9\times 36}{25\times 16}=\frac{81}{100}=0/81$