Đáp án:
\(\begin{array}{l}
1.\\
a.\\
R = 15\Omega \\
I = 0,8A\\
b.\\
{R_3} = 15\Omega \\
2.\\
a.\\
Q = 680000J\\
b.\\
{Q_{toa}} = 1680000J\\
c.\\
\$ = 92000d
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
1.\\
a.\\
R = {R_1} + {R_2} = 5 + 10 = 15\Omega \\
I = \frac{U}{R} = \frac{{12}}{{15}} = 0,8A\\
b.\\
I' = \frac{I}{2} = \frac{{0,8}}{2} = 0,4A\\
R' = \frac{U}{I} = \frac{{12}}{{0,4}} = 30\Omega \\
{R_3} = R' - R = 30 - 15 = 15\Omega \\
2.\\
a.\\
Q = mc(t' - t) = 5.4200(100 - 20) = 1680000J\\
b.\\
{Q_{toa}} = {Q_{thu}} = Q = 1680000J\\
c.\\
A = Pt = 2000.4.30 = 240000Wh = 240kWh\\
\$ = A.800 = 240.800 = 192000d
\end{array}\)
