Question

giup em voi, em cam on

Answer 1

a)\(R_1//R_2\Rightarrow R_{12}=\dfrac{R_1\cdot R_2}{R_1+R_2}=\dfrac{60\cdot40}{60+40}=24\Omega\)

\(I=\dfrac{U}{R_{tđ}}=\dfrac{12}{24}=0,5A\)

b)\(U_1=U_2=U=12V\)

\(P_1=\dfrac{U_1^2}{R_1}=\dfrac{12^2}{60}=2,4W\)

\(P_2=\dfrac{U_2^2}{R_2}=\dfrac{12^2}{40}=3,6W\)

c)CTM mới: \(R_3nt(R_1//R_2)\)

\(I'=\dfrac{I}{2}=\dfrac{0,5}{2}=0,25A\)

\(R_{tđ}=\dfrac{U}{I'}=\dfrac{12}{0,25}=48\Omega\)

\(R_3=R_{tđ}-R_{12}=48-24=24\Omega\)