\(R_{tđ}=R_1+R_2=6+12=18\left(\Omega\right)\)
\(P=I^2.R\)
\(\Rightarrow I=I_1=I_2=\sqrt{\dfrac{P}{R}}=\sqrt{\dfrac{36}{18}}=\sqrt{2}\left(A\right)\)
\(P_1=I_1^2.R_1=2.6=12\left(W\right)\)
=> Chọn B
\(P=\dfrac{U^2}{R}\Rightarrow U=\sqrt{P.R}=\sqrt{36.\left(6+12\right)}\simeq25,5\left(\Omega\right)\)
\(I=I1=I2=U:R=25,5:\left(6+12\right)=\dfrac{17}{12}A\left(R1ntR2\right)\)
\(\Rightarrow P1=U1.I1=\left(6.\dfrac{17}{12}\right)\dfrac{17}{12}\simeq12\)W
Chọn B
\(R_{tđ}=R_1+R_2=6+12=18\Omega\)
\(I^2_m=\dfrac{P}{R_{tđ}}=\dfrac{36}{18}=2A\) \(\Rightarrow I_1=I_2=I_m=\sqrt{2}A\)
\(P_1=I^2_1\cdot R_1=\left(\sqrt{2}\right)^2\cdot6=12W\)
Chọn B.
