Đáp án:
\(\begin{align}
& {{P}_{dm1}}=60\text{W} \\
& {{P}_{dm2}}=40\text{W} \\
& {{P}_{dm3}}=30\text{W} \\
\end{align}\)
Giải thích các bước giải:
\(\begin{align}
& {{U}_{1}}={{U}_{2}}={{U}_{3}}=220V \\
& {{P}_{dm1}}+{{P}_{dm2}}+{{P}_{dm3}}=130\text{W} \\
& {{P}_{dm1}}=\dfrac{3}{2}{{P}_{dm2}} \\
& {{P}_{dm2}}=\dfrac{4}{3}{{P}_{dm3}} \\
\end{align}\)
công suất định mức mỗi đèn:
\(\begin{align}
& \dfrac{3}{2}{{P}_{dm2}}+{{P}_{dm2}}+\dfrac{3}{4}{{P}_{dm2}}=130 \\
& \Rightarrow \dfrac{13}{4}{{P}_{dm2}}=130 \\
& \Rightarrow {{P}_{dm2}}=40\text{W} \\
\end{align}\)
\(\begin{align}
& {{P}_{dm1}}=\dfrac{3}{2}{{P}_{dm2}}=\dfrac{3}{2}.40=60\text{W} \\
& {{P}_{dm3}}=130-40-60=30\text{W} \\
\end{align}\)