parallel resistance.

[searley]

A resistor network with three resistors 9Ω, 3Ω, 12Ω are connected in parallel. What will their combined resistance be:

can i work this out on a scientific calculator ? cheers.

 

[SPECIAL LOCATION]

have a look at this thread searley

http://www.talk.electricianforum.co.uk/showthread.php?t=1221&highlight=parallel

it goes thorough parallel resistance calcs quite well..

save us typing the same out again..

if still got probs.. post the bit you don't understand!

 

[searley]

i try`ed 1 over 9 + 1over 3 + 1 over 12 and i got 0.52.the answer on the sheet is 1.89 ohms :_| :_| :_| .

 

[Theorysparky]

you forgot to divide that by 1

1/Rt=1/r +1/r +1/r

 

[SPECIAL LOCATION]

i try`ed 1 over 9 + 1over 3 + 1 over 12 and i got 0.52.the answer on the sheet is 1.89 ohms :_| :_| :_| .

As Theory said..

1/Rt=1/r +1/r +1/r

but you may just need to check the number of decimal places you are working to

e.g.

1/9 = 0.111

1/3 = 0.333

1/12 = 0.083

= 0.527

1/0.527 = 1.89

WHEREAS 1/0.52 = 1.92!!!

Not sure what the trend is nowadays..

But I was told as a general rule.. (unless specified in the question)..

work to 3 decimal places for added bit of accuracy without having reams of long numbers written down.

 

[searley]

got it.thanks for all the help. top men.

 

[mysticalelectrickery]

oops

 

[Mr Sworld]

A resistor network with three resistors 9Ω, 3Ω, 12Ω are connected in parallel. What will their combined resistance be:can i work this out on a scientific calculator ? cheers.

How did you get the Ohm symbol to appear?

 

[Theorysparky]

How did you get the Ohm symbol to appear?

ΩΩΩ

the only way i got it was to open a word document,,,,,,symbols

copy + paste and i bet thats the long way round:O

 

[SPECIAL LOCATION]

ΩΩΩthe only way i got it was to open a word document,,,,,,symbols

copy + paste and i bet thats the long way round:O

you could just copy it from the post on this ere fornumGuiness Drink

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makes me feel like burstin into song...

Guiness DrinkGuiness Drink

ohm ohm on the range...

where the deer and the antelope play...

there seldom is heard...

a discouraging word.........

BlushingBlushing

oops

sorry!!!

I am now sitting back in me corner...

and I am about to put m y h a n d s o n m e h e a d.

{had to type them last bits with me nose... and this bit was typed..

and copied earlier.. then just pasted with me nose! :|}