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kira506
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Homework Statement
It is required to transfer an electric power of 80. Kilowatts from a powerstation to a factory which is at 2 km from it.If the potential difference (here it means the voltage of the source) at the station is 400 volts and the resistance of 1km of the 2 conducting wires is 0.1 ohm, find the power lost
Homework Equations
Power=VI (where v here is the potential difference between the source ie: power station and the output : factory ) or I^2.R
voltage in secondary coil(factory)/voltage in primary coil (station)=current intensity in primarycoil/current intensity in secondarycoil
The Attempt at a Solution
P= VI
80000=400I ,I=200 ampere
Here's the tricky part for me , In case of connecting the 2 wires in parallel , resistance of one wire = 2*0.1=0.2ohm
Rtotal=0.2/2 (since the 2 wires have the same length and assumingly made of the same material and have the same cross sectional area ,therefore we consider their value)=0.1ohm
The model answer shows that Rtotal =0.4 ohm ,how ,? We won't get this value unless we connect them in series and usually in these kinds of problems the wires are connected in parallel ,besides , nothing in the problem indicates the kind of connection , please help
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