# Volts and Amps

Discussion in 'General Electronics Discussion' started by John Steaver, Oct 28, 2015.

1. ### John Steaver

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Oct 28, 2015
Could you add amps onto volt or take away amps from volts?
Thanks

2. ### davennModerator

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Sep 5, 2009
hi John,
welcome

no it doesn't work quite like that

here's the Ohms Law Triangle showing how Volts, Amps (current) and Resistance interact with each other

Last edited: Oct 28, 2015
3. ### John Steaver

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Oct 28, 2015
so what would happen if you tried? Would it still be the same voltage?

4. ### davennModerator

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Sep 5, 2009
As I said, you cannot, it doesn't work that way

now lets look at a practical circuit

So using the Ohms law triangle from my first post
can you tell me the current flowing in this circuit ?

Dave

35
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Oct 28, 2015
1 amp?

6. ### davennModerator

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Sep 5, 2009
yes

now change the battery voltage to 25V
what is the current flowing now ?

Dave

7. ### Colin Mitchell

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Aug 31, 2014
You have to write a question using voltage and amps and we will correct it.

8. ### davennModerator

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Sep 5, 2009
note that in a series circuit, the current flow is the same everywhere
so the current flowing through A1 at the top is the same as the current flowing through A2 at the bottom

9. ### davennModerator

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Sep 5, 2009
he's doing OK Colin, don't confuse him yet, lets work out way up

10. ### John Steaver

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Oct 28, 2015
2.5 amps? I think I get now, thanks for replying so quickly

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11. ### davennModerator

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Sep 5, 2009
Yup
so experiment with changing the resistor value, whilst keeping the voltage value constant
see the effect that has on the current value

cheers
Dave

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12. ### BobK

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Jan 5, 2010
Despite others attempts to answer, I have no clue what you are asking.

Amps and volts measure two different things, it makes no sense to add one to the other or subtract one from the other. So the answer is yes, you could, but the result would be totally meaningless. For example what is 10V + 5A (the answer is 15, but 15 what?)

Please explain what you are really thinking (which is what I think Colin was trying to ask.)

Bob

13. ### davennModerator

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Sep 5, 2009

he's now on the right path, Bob,
He just didn't understand the relationship between volts and amps

Dave

14. ### Martaine2005

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May 12, 2015
I think you are doing a great job Dave of being a monitor! Make sure the threads don't go off track.
He will learn faster without being confused by people like @CDRIVE .

Keep up the good work.

15. ### duke37

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Jan 9, 2011
I am 1.8m tall and weigh 99kg. How can I add these? In fact, I need to do some subtraction.

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16. ### davennModerator

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Sep 5, 2009

hahaha yeah me too. if I was 99kg, I would be extremely happy (anywhere between 100 - 110kg would be awesome)

D

17. ### davennModerator

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Sep 5, 2009
lol and this one is heading that way too, so lets stop whilst we are ahead

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18. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012
I'm here because the forum alerts said that Marty quoted me, mentioned my name or ... hell I don't know but I'm here, so let's try this. Way back when Dinosaurs ruled I was teaching basic industrial electronics. To help my students relate to the material world I told them to think of electrical circuits as plumbing, where Voltage is pressure, like (PSI) pounds per square inch. Current in Amps is equivalent to water "flowing" though the pipes and measured in gallons per minute (GPM). And finally Resistance (R) as being equivalent to how much water you can push through a 1/2" pipe in one minute as compared to a 2" pipe. The smaller the pipe the higher the resistance (Restriction) to water flow. The larger the pipe, the lower the resistance (restriction) to water flow. Think of a 1Ω resistor as a big pipe and a 10KΩ resistor as a small pipe.

So if you grasp this you will see that "arbitrarily" doing math on any three of of the Ohms Law (a brilliant guy) elements is meaningless. Heck, that's why it called Ohm's "LAW". If you violate it you go to electronics San Quentin.

Chris

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19. ### Martaine2005

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May 12, 2015
SHhh..........

20. ### BobK

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Jan 5, 2010
Yes, and they will tack on a charge of resisting arrest.

Bob

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