[tex]\text{Stim ca:}\\
W=E\cdot I\cdot t,\text{unde W energia electrica,E -tensiunea ,I-intensitatea}\\
\text{si t -timpul}\\
\text{Deci:}\\
E=\dfrac{W}{I\cdot t}\\
E=\dfrac{4400 J}{20\ A\cdot 1\ s}=\dfrac{4400\ J}{20\ A\cdot s}= 220\ V\\
\boxed{E=220\ V}
[/tex]
