Odpowiedź :
Odpowiedź:
U = 230 V
I = 1,5A
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a)
P ?
P=U*I = 230V*1,5A = 345 W
P =345 W
b)
U₂=200 V
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P₂ = ?
R = U/I = 230V/1,5 A = 153,3 Ω
I₂ = U₂/R = 200V/153,3Ω = 1,3 A
P₂ = U₂*I₂ = 200V*1,3A = 260 W
P₂ = 260 W
c)
t = 20 min = 1/3 h = 1200s
P = 345W = 0,345 kW
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W ?
W = P*t = 0,345W* 1/3h = 0,115 kWh
W = 0,115 kWh
W = P*t = 345W* 1200s = 414 000 J = 414 kJ
W = 414 kJ