Electricity question

JohnCU

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Let's say you have a voltmeter, and have the positive test lead touching the positive end of a battery, and the negative plugged into the neutral socket of a wall outlet. Why does it not read the voltage of the battery? Voltage is relative from point to point, and the wall should be at 0, and the battery should be 1.5 V, so it should read 1.5 V shouldn it?
 

KLin

Lifer
Feb 29, 2000
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Originally posted by: HappyPuppy
I'm sorry, I really don't know how to respond to your query without confusing you even more.

Translated - "You're too stupid to comprehend my explanation."

 

Heisenberg

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Dec 21, 2001
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Because the voltage of the positive end of the battery is produced relative to the negative end, not the ground.
 

element

Diamond Member
Oct 9, 1999
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the battery is not connected to the ground of the house so no it won't read the voltage as 1.5 because there is no current flow through the voltmeter. However, the potential difference is theoretically 1.5 volts.
 

JohnCU

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Dec 9, 2000
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Originally posted by: Pepsi90919
well for one thing you can't read AC and DC at the same time... :) among lots of other things

Ground is ground, isn't it? I mean, 0 volts is 0 volts, the ground isn't sinusoidal.
 

Pepsi90919

Lifer
Oct 9, 1999
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Originally posted by: JohnCU
Originally posted by: Pepsi90919
well for one thing you can't read AC and DC at the same time... :) among lots of other things

Ground is ground, isn't it? I mean, 0 volts is 0 volts, the ground isn't sinusoidal.

AC doesn't have a ground
 

Heisenberg

Lifer
Dec 21, 2001
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Originally posted by: Pepsi90919
Originally posted by: JohnCU
Originally posted by: Pepsi90919
well for one thing you can't read AC and DC at the same time... :) among lots of other things

Ground is ground, isn't it? I mean, 0 volts is 0 volts, the ground isn't sinusoidal.

AC doesn't have a ground
Err...what? All electricity requires two points to have a potential difference whether it's AC or DC.
 

Pepsi90919

Lifer
Oct 9, 1999
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Originally posted by: Heisenberg
Originally posted by: Pepsi90919
Originally posted by: JohnCU
Originally posted by: Pepsi90919
well for one thing you can't read AC and DC at the same time... :) among lots of other things

Ground is ground, isn't it? I mean, 0 volts is 0 volts, the ground isn't sinusoidal.

AC doesn't have a ground
Err...what? All electricity requires two points to have a potential difference whether it's AC or DC.

it's neutral
 

JohnCU

Banned
Dec 9, 2000
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Originally posted by: Pepsi90919
Originally posted by: Heisenberg
Originally posted by: Pepsi90919
Originally posted by: JohnCU
Originally posted by: Pepsi90919
well for one thing you can't read AC and DC at the same time... :) among lots of other things

Ground is ground, isn't it? I mean, 0 volts is 0 volts, the ground isn't sinusoidal.

AC doesn't have a ground
Err...what? All electricity requires two points to have a potential difference whether it's AC or DC.

it's neutral

There is a 3rd prong that connects to the ground for safety precautions, or have I spent 2 years in EE for nothing?
 

Heisenberg

Lifer
Dec 21, 2001
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Originally posted by: Pepsi90919
Originally posted by: Heisenberg
Originally posted by: Pepsi90919
Originally posted by: JohnCU
Originally posted by: Pepsi90919
well for one thing you can't read AC and DC at the same time... :) among lots of other things

Ground is ground, isn't it? I mean, 0 volts is 0 volts, the ground isn't sinusoidal.

AC doesn't have a ground
Err...what? All electricity requires two points to have a potential difference whether it's AC or DC.

it's neutral
Well neutral or ground or whatever the hell you want to call it, AC still requires a reference point of that's defined to be zero potential.
 

element

Diamond Member
Oct 9, 1999
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you spent 2 years in EE and don't know the answer to your question? I hate to say this but that's sad
 

Pepsi90919

Lifer
Oct 9, 1999
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Originally posted by: JohnCU
Originally posted by: Pepsi90919
Originally posted by: Heisenberg
Originally posted by: Pepsi90919
Originally posted by: JohnCU
Originally posted by: Pepsi90919
well for one thing you can't read AC and DC at the same time... :) among lots of other things

Ground is ground, isn't it? I mean, 0 volts is 0 volts, the ground isn't sinusoidal.

AC doesn't have a ground
Err...what? All electricity requires two points to have a potential difference whether it's AC or DC.

it's neutral

There is a 3rd prong that connects to the ground for safety precautions, or have I spent 2 years in EE for nothing?
:confused:

if you spent 2 years in EE i'm sure you'd be able to answer the original question.
 

JohnCU

Banned
Dec 9, 2000
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Originally posted by: element
you spent 2 years in EE and don't know the answer to your question? I hate to say this but that's sad

Well, relative to the ground, the battery's positive end is at 1.5 V, no?
 

Pepsi90919

Lifer
Oct 9, 1999
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Originally posted by: JohnCU
Originally posted by: element
you spent 2 years in EE and don't know the answer to your question? I hate to say this but that's sad

Well, relative to the ground, the battery's positive end is at 1.5 V, no?

>.<

aside from the obvious AC and DC discrepancy, there's no completed circuit in the battery. there are no electrons flowing anywhere.
 

element

Diamond Member
Oct 9, 1999
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Originally posted by: JohnCU
Originally posted by: element
you spent 2 years in EE and don't know the answer to your question? I hate to say this but that's sad

Well, relative to the ground, the battery's positive end is at 1.5 V, no?

yes theoretically. as I stated before, you might have missed it:

the battery is not connected to the ground of the house so no it won't read the voltage as 1.5 because there is no current flow through the voltmeter. However, the potential difference is theoretically 1.5 volts.
 

JohnCU

Banned
Dec 9, 2000
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Originally posted by: Pepsi90919
Originally posted by: JohnCU
Originally posted by: element
you spent 2 years in EE and don't know the answer to your question? I hate to say this but that's sad

Well, relative to the ground, the battery's positive end is at 1.5 V, no?

>.<

aside from the obvious AC and DC discrepancy, there's no completed circuit in the battery. there are no electrons flowing anywhere.

Well, in a perfect voltmeter, there is infinite resistance, so there's no completed circuit when you touch the two leads together.
 

Pepsi90919

Lifer
Oct 9, 1999
25,162
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Originally posted by: JohnCU
Originally posted by: Pepsi90919
Originally posted by: JohnCU
Originally posted by: element
you spent 2 years in EE and don't know the answer to your question? I hate to say this but that's sad

Well, relative to the ground, the battery's positive end is at 1.5 V, no?

>.<

aside from the obvious AC and DC discrepancy, there's no completed circuit in the battery. there are no electrons flowing anywhere.

Well, in a perfect voltmeter, there is infinite resistance, so there's no completed circuit when you touch the two leads together.
i don't see where you're going with this...