Question

Giúp e vs ạa

Answer 1

Bạn tự vẽ sơ đồ mạch điện nha.

\(MCD:R1//R2\)

\(\Rightarrow R=\dfrac{R1\cdot R2}{R1+R2}=\dfrac{10\cdot15}{10+15}=6\Omega\)

\(U1=U2=U=12V\Rightarrow\left[{}\begin{matrix}I1=\dfrac{U1}{R1}=\dfrac{12}{10}=1,2A\\I2=\dfrac{U2}{R2}=\dfrac{12}{15}=0,8A\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}P1=U1\cdot I1=12\cdot1,2=14,4\left(W\right)\\P2=U2\cdot I2=12\cdot0,8=9,6\left(W\right)\end{matrix}\right.\)

\(MCD:R3nt\left(R1//R2\right)\)

\(\Rightarrow R'=R3+R=4+6=10\Omega\)

\(\Rightarrow I'=I3=I12=\dfrac{U}{R'}=\dfrac{12}{10}=1,2A\)

\(\rightarrow U12=U1=U2=U-U3=12-\left(1,2\cdot4\right)=7,2V\Rightarrow\left[{}\begin{matrix}I1'=\dfrac{U1'}{R1}=\dfrac{7,2}{10}=0,72A\\I2'=\dfrac{U2'}{R2}=\dfrac{7,2}{15}=0,48A\end{matrix}\right.\)