Se da:
U=220V
t=20min=1200s
Q=1,05MJ=1050000J
T=1,6 lei/kW*h=1,6lei/3,6MJ
I=?A
P=?W
S=?lei
Formule:
Q=I²Rt
Q=IUt
I=Q/Ut
Q=Pt
P=Q/t
T=S*L
T=S*Q, la tarif voi folosi 1,05MJ, pentru ca sa se simplifice MJ
Calcule:
I=1050000/220*1200=3,977A
P=1050000/1200=875W
T=1,6*1,05=1,68lei