a) Se dă: U=L/q
I=0,28A q=I*t
t=3h=10800s q=0,28A*10800s=3024C
L=6,72W*h=6,72W*3600s=24192J U=24192J/3024C=8V
U-?
b)P=60W L=P*t
t=6h(30 zile)=21600s(1zi)=648000s(30 zile) L=60W*648000s=38880000J
п=1,6 lei P=38880kJ/3600=10,8kW
П-? П=10,8kW*1,6 lei=17,28 lei