Physik – einfacher Stromkreis?
Wie ist die Aufgabe gemeint? Unser Lehrer sagte, man muss die Länge mal zwei nehmen, aber wieso?
Ein Verbraucher ist über eine 500 m vom Speisepunkt entfernte, 3 mm dicke Aluminiumleitung (Aluminium: rho = 0, 286 ohm x mm^2/m) mit der Spannungsquelle verbunden. Bei Belastung mit I = 5A beträgt die Klemmspannung 189,8 V. Wie groß ist die Klemmspannung bei Belastung mit I= 10 A?
> one must take the length once two
No. You must the distance take two, then you get the length of the wire through which the current must flow.
Look at the unit of rho. … there is …/m, so per meter. If the consumer is 500 m away from the power source, you need 1000 m cable. Of course you have the resistance of 1000 m cable.
Because the current flows and back. In this way you need the length twice.
But not for R or? I reckon rho x L:A
Yes. You have the line resistance from the information, and you need 2x. In addition, the consumer. So you have a series connection of 2x of the line and an unknown consumer.
And for U = I x R x 2?
You have a line 500x to the consumer with a resistor R, then a consumer, then a line 500m back to the source with a resistor R. Insofar 2x the line resistor R.
Why the resistance? In the head, he remains the same
Because the power has to go back and forth
But I don’t even take the tension that comes with me because it’s just the way out?