Bulb consumption hours

A current of 500 mA passed through the filament of a light bulb with a resistance of 400 ohms. What is the consumption of a light bulb in 5 hours?

Final Answer:

W =  500 Wh

Step-by-step explanation:

$$\begin{gathered} R=400\Omega \\ I=500\text{mA}\to \text{A}=500:1000\text{A}=0.5\text{A} \\ t=5\text{h} \\ P=R\cdot I^2=400\cdot 0.5^2=100\text{W} \\ W=P\cdot t=100\cdot 5=500\text{Wh} \end{gathered}$$

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