Energy consumption

The device is connected to 230V and draws a 3.5A current. Power consumption is 1932kJ. How many minutes has this device been in operation?

Final Answer:

t =  40 min

Step-by-step explanation:

$$\begin{gathered} U=230\text{V} \\ I=3.5\text{A} \\ W=1932\text{kJ}\to \text{J}=1932\cdot 1000\text{J}=1932000\text{J} \\ P=U\cdot I=230\cdot 3.5=805\text{W} \\ W=Pt \\ {t}_1=W/P=1932000/805=2400\text{s} \\ t=t_1\to \text{min}=t_1:60\text{min}=2400:60\text{min}=40\text{min}=40\text{min} \end{gathered}$$

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