\(U_1=R_1\cdot I_1=1\cdot0,5=0,5V\)
\(U_2=U_3=U_{23}=12-0,5=11,5V\)
\(I_{23}=I_1=0,5A\)
\(\Rightarrow R_{23}=\dfrac{U_{23}}{I_{23}}=\dfrac{11,5}{0,5}=23\Omega\)
\(\Rightarrow\dfrac{1}{R_{23}}=\dfrac{1}{R_2}+\dfrac{1}{R_3}\Rightarrow R_2=\)âm
Đề vô lí
MCD: \(R1nt\left(R2//R3\right)\)
a. \(I=I1=I2=0,5A\)
\(\rightarrow R=U:I=12:0,5=24\Omega\)
\(\rightarrow R23=R-R1=24-1=23\Omega\)
\(\dfrac{1}{R23}=\dfrac{1}{R2}+\dfrac{1}{R3}\Rightarrow\dfrac{1}{R2}=\dfrac{1}{R23}-\dfrac{1}{R3}=\dfrac{1}{23}-\dfrac{1}{3}=\dfrac{-20}{69}\Rightarrow R=\dfrac{-69}{20}\Omega\)
Hình như đề sai số rồi thì phải?
