Question

Answer 1

Ta có mạch điện (R1ntR2)//R3

a, \(R_{12}=R_1+R_2=10+20=30\left(\Omega\right)\)

\(\dfrac{1}{R_{tđ}}=\dfrac{1}{R_{12}}+\dfrac{1}{R_3}=\dfrac{1}{30}+\dfrac{1}{30}=\dfrac{1}{15}\Leftrightarrow R_{tđ}=15\left(\Omega\right)\)

\(I_m=\dfrac{U_{AB}}{R_{tđ}}=\dfrac{6,75}{15}=0,45\left(A\right)\)

b, \(U_{AB}=U_{12}=U_3=6,75\left(V\right)\)

\(I_{12}=\dfrac{U_{12}}{R_{12}}=\dfrac{6,75}{30}=0,225\left(A\right)=I_2=I_A\)

Answer 2

Cho hỏi R ở dưới là R gì v ? R2 hay R3