Watt-ul este unitatea de masura pentru putere(in cazul nostru electrica). Astfel becul are nevoie ca cineva sa-i dea 100W ca sa poata functiona normal. Energia electrica se calculeaza inmultind puterea cu timpul cat a fost solicitata puterea respectiva. Cu alte cuvinte becul de 100 W va consuma, daca functioneaza 1 ora 100Wh(0, 1kWh) iar daca va functiona 10 ore va consuma in total 1kWh.
Bft
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