another question

[NWDS]

sorry all,

Three pvc insulated cables are connected in parallel, and their resistances are 0.012, 0.015 and 0.008,respectivley,with a total current of 500A flowing on a 240V supply,

A, calculate the current in each cable ( V/R = I )

B, calculate the combined voltage drop over the three cables in parallel,

C, calculate the individual voltage drop over each cable in the paralleled circuit.

I have worked out resistance,

1/0.012 = 83.33 so V/R = I ( 240/0.012 = 20,000 )

1/0.015 = 66.66 so V/R = I (240/0.015 = 16,000 )

1/0.008 = 125 so V/R = I ( 240/0.008 = 30,000 )

am i using the correct formula ( NO ) ???????.

regards NWDS headbangheadbangheadbangheadbangheadbangheadbangheadbangheadbangheadbangheadbangheadbang

 

[jl-heating]

i got lost at " 3 pvc insulated cables "

 

[Dane]

i got lost at " 3 pvc insulated cables "

mention PVC to john and he goes a bit giddy]

I can always remember the formula much easier as Current = Power / Voltage

 

[Andy™]

Ignore this post... kinda got it wrong

 

[NWDS]

thanks Andy, I will copy that so I can go back to it.

NWDS

Applaud SmileyApplaud SmileyApplaud SmileyApplaud SmileyApplaud SmileyApplaud SmileyApplaud Smiley

 

[NWDS]

the answers in me book are

A, 152A,121A and 227A ( all add up to the total current given )

B, 1.82 v

C,1.82 v

NWDS

 

[Andy™]

the answers in me book areA, 152A,121A and 227A ( all add up to the total current given )

B, 1.82 v

C,1.82 v

NWDS

then the book is wrong. VD over all has got to be 240V - there is no other resistances, and the supply voltage is 240V.

C, should there be 3 values? anyway that answer still looks wrong

 

[NWDS]

thanks andy

NWDS

Applaud SmileyApplaud SmileyApplaud Smiley

 

[NWDS]

Andy can you explain why you added up the 3 resistences ( I thought they were in parallel ), I understand the rest but not that BlushingBlushingBlushingBlushingBlushingBlushing.

NWDS

 

[Andy™]

Andy can you explain why you added up the 3 resistences ( I thought they were in parallel ), I understand the rest but not that BlushingBlushingBlushingBlushingBlushingBlushing.NWDS

forget what i first said... got the right answers, but in the wrong order... ill work it out again tomorrow, unless someone beats me to it