Circuit voltage

Calculate the closed-circuit voltage. Calculate the power on the resistors. R1 = 30 ohms, R2 = 10 ohms. I = 0.1A. U =?. The resistors are connected in series, one after the other.

Correct answer:

P₁ =  0.3 W
P₂ =  0.1 W
U =  4 V

Step-by-step explanation:

$$\begin{gathered} R_1=30\Omega \\ {R}_2=10\Omega \\ I=0.1\text{A} \\ {U}_1=I\cdot R_1=0.1\cdot 30=3\text{V} \\ {P}_1=U_1\cdot I=3\cdot 0.1=0.3\text{W} \end{gathered}$$

$$\begin{gathered} U_2=I\cdot R_2=0.1\cdot 10=1\text{V} \\ {P}_2=U_2\cdot I=1\cdot 0.1=0.1\text{W} \end{gathered}$$

$U=U_1+U_2=3+1=4\text{V}$

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