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Resistivity watch

1. Work out the resistance of 1.0 km of the cable by treating the wires making up the cable as resistances in parallel

do P=V2/R
2. (Original post by Joinedup)
Work out the resistance of 1.0 km of the cable by treating the wires making up the cable as resistances in parallel

do P=V2/R
So do 75^2/(1.1/6)
3. (Original post by Ayaz789)
So do 75^2/(1.1/6)
That's just the 6 aluminium wires... the steel wire should also be included
4. (Original post by Joinedup)
That's just the 6 aluminium wires... the steel wire should also be included
So its 75^2/(1.1/6)+3.3?
5. (Original post by Ayaz789)
So its 75^2/(1.1/6)+3.3?

should be getting 752/0.17 for 33kW
6. (Original post by Joinedup)
should be getting 752/0.17 for 33kW
How did you get 0.17 on the bottom?
7. (Original post by Ayaz789)
How did you get 0.17 on the bottom?
1/R=1/R1+1/R2...
so
R=1/(1/1.1+1/1.1+1/1.1+1/1.1+1/1.1+1/1.1+1/3.3)
or
R=1/(6*(1/1.1)+1/3.3)
8. (Original post by Joinedup)
1/R=1/R1+1/R2...
so
R=1/(1/1.1+1/1.1+1/1.1+1/1.1+1/1.1+1/1.1+1/3.3)
or
R=1/(6*(1/1.1)+1/3.3)
Okay thanks i understand it

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