Question

Answer 1

\(=>P=U.I=\dfrac{U^2}{R}=>R=\dfrac{U^2}{P}=\dfrac{220^2}{70}=\dfrac{4840}{7}\left(om\right)\)

\(=>I\left(đm\right)=\dfrac{P}{U}=\dfrac{70}{220}\approx0,32A\)

\(=>I\left(thuc-te\right)=\dfrac{U\left(thuc-te\right)}{R}=\dfrac{210}{\dfrac{4840}{7}}\approx0,3A< I\left(đm\right)\)

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