What is one volt?

Bill Bowden · Feb 16, 2016

I see the voltaic pile produces a voltage of about 1 volt, but not exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also 1
ohm. But I don't get the second part of 1 newton per coulomb across two
infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between two
points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal to
the potential difference between two parallel, infinite planes spaced 1
meter apart that create an electric field of 1 newton per coulomb."

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

John Larkin · Feb 16, 2016

On Mon, 15 Feb 2016 20:01:15 -0800, "Bill Bowden"
<bperryb@bowdenshobbycircuits.info> wrote:

I see the voltaic pile produces a voltage of about 1 volt, but not exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also 1
ohm. But I don't get the second part of 1 newton per coulomb across two
infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between two
points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal to
the potential difference between two parallel, infinite planes spaced 1
meter apart that create an electric field of 1 newton per coulomb."

If you charged a ball bearing with one coulomb of electrons, and
suspended it midway between two conductive planes that are 1 meter
apart and with a potential difference of 1 volt, the force on the ball
bearing would be 1 newton.

Of course, that ball bearing would have to be charged to about a
trillion volts. Maybe using one electron would be more practical.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

Helmut Wabnig · Feb 16, 2016

On Mon, 15 Feb 2016 20:01:15 -0800, "Bill Bowden"
<bperryb@bowdenshobbycircuits.info> wrote:

I see the voltaic pile produces a voltage of about 1 volt, but not exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also 1
ohm. But I don't get the second part of 1 newton per coulomb across two
infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between two
points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal to
the potential difference between two parallel, infinite planes spaced 1
meter apart that create an electric field of 1 newton per coulomb."

to me this is clear.
What is your problem?

Of course one cannot build a real laboratory voltage reference
from that.
In olde times they used a Mercury thread of 1 mm square
and 1 meter lenght to build 1 Ohm.

The Ampere definition is similar::
The basic unit of electric current, equal to one coulomb per second
and equivalent to the current, flowing in two straight parallel wires
of negligible cross section separated by a distance of one meter, that
produces a force between the wires of 2.0 × 10-7 newtons per meter of
length. The value of an ampere in the International System differs
very slightly from that in the meter-kilogram-second-ampere system of
units.

Equally unuseable to build a real laboratory device.
The Ohm:
It was first agreed that this theoretical ohm should be represented
by the resistance offered to an unvarying current of electricity by
a column of mercury one square millimeter in cross section and one
hundred and six centimeters in length.

From there to "legal units" is a long way.
Actually you buy a voltmeter and rely on the manufacturer.

w.

George Herold · Feb 16, 2016

On Monday, February 15, 2016 at 11:01:21 PM UTC-5, Bill Bowden wrote:

I see the voltaic pile produces a voltage of about 1 volt, but not exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also 1
ohm. But I don't get the second part of 1 newton per coulomb across two
infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between two
points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal to
the potential difference between two parallel, infinite planes spaced 1
meter apart that create an electric field of 1 newton per coulomb."

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

I'll probably get this wrong, But the volt is a derived unit.
We measure resistance (from the quantized hall effect.)
and time... from atomic transitions, and then define the charge
of the electron (I think) and from these get current and the volt follows.

George H.

Tim Wescott · Feb 16, 2016

On Mon, 15 Feb 2016 20:01:15 -0800, Bill Bowden wrote:

I see the voltaic pile produces a voltage of about 1 volt, but not
exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also 1
ohm. But I don't get the second part of 1 newton per coulomb across two
infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between two
points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal
to the potential difference between two parallel, infinite planes spaced
1 meter apart that create an electric field of 1 newton per coulomb."

An electric field generates a force on a charge.

A coulomb is a defined number of charges.

A voltage is required to set up an electric field.

The longer a distance an electric field is set up over, the higher the
voltage needed to create the field (this is why high-voltage parts have
large spacing between conductors).

So they're saying that if you have a pair of infinite plates, one meter
apart, with one volt between them, that the electric field in between the
plates will have a strength of one newton per coulomb.

To actually DO the experiment you'd use some lesser charge (like an
electron), some other arrangement of charged conductors (finite-sized
plates spaced closer together), some other voltage (probably), and you'd
do a bunch of math to work out the relationship.

--
www.wescottdesign.com

whit3rd · Feb 16, 2016

On Tuesday, February 16, 2016 at 1:13:32 AM UTC-8, Helmut Wabnig wrote:

The Ampere definition is similar::
The basic unit of electric current, equal to one coulomb per second
and equivalent to the current, flowing in two straight parallel wires
of negligible cross section separated by a distance of one meter, that
produces a force between the wires of 2.0 Đ˛ 10-7 newtons per meter of
length.

Equally unuseable to build a real laboratory device.

Oh, but that is usable. It's basically the same as a two-coil d'Arsonval
meter movement (with scale and geometry constant factors).

whit3rd · Feb 16, 2016

On Monday, February 15, 2016 at 8:41:59 PM UTC-8, John Larkin wrote:

If you charged a ball bearing with one coulomb of electrons, and
suspended it midway between two conductive planes that are 1 meter
apart and with a potential difference of 1 volt, the force on the ball
bearing would be 1 newton.

Of course, that ball bearing would have to be charged to about a
trillion volts. Maybe using one electron would be more practical.

Of course. One uses an electron instead, and observes the trajectory
in a cathode-ray tube with electrostatic deflection.

John Larkin · Feb 16, 2016

On Tue, 16 Feb 2016 07:40:52 -0800 (PST), George Herold
<gherold@teachspin.com> wrote:

On Monday, February 15, 2016 at 11:01:21 PM UTC-5, Bill Bowden wrote:
I see the voltaic pile produces a voltage of about 1 volt, but not exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also 1
ohm. But I don't get the second part of 1 newton per coulomb across two
infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between two
points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal to
the potential difference between two parallel, infinite planes spaced 1
meter apart that create an electric field of 1 newton per coulomb."

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

I'll probably get this wrong, But the volt is a derived unit.
We measure resistance (from the quantized hall effect.)
and time... from atomic transitions, and then define the charge
of the electron (I think) and from these get current and the volt follows.

George H.

Most everything is a derived unit.

The volt is now defined in terms of frequency, through a
superconducting Josephson junction.

Wiki says...

The kilogram is the only SI base unit with an SI prefix ("kilo",
symbol "k") as part of its name. It is also the only SI unit that is
still directly defined by an artifact rather than a fundamental
physical property that can be reproduced in different laboratories.
Three other base units (Cd, A, mol) and 17 derived units (N, Pa, J, W,
C, V, F, O, S, Wb, T, H, kat, Gy, Sv, lm, lx) in the SI system are
defined relative to the kilogram, so its stability is important. Only
8 other units do not require the kilogram in their definition:
temperature (K, °C), time and frequency (s, Hz, Bq), length (m), and
angle (rad, sr).[4]:112118

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

Tim Wescott · Feb 17, 2016

On Tue, 16 Feb 2016 09:25:10 -0800, John Larkin wrote:

On Tue, 16 Feb 2016 07:40:52 -0800 (PST), George Herold
gherold@teachspin.com> wrote:

On Monday, February 15, 2016 at 11:01:21 PM UTC-5, Bill Bowden wrote:
I see the voltaic pile produces a voltage of about 1 volt, but not
exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also
1 ohm. But I don't get the second part of 1 newton per coulomb across
two infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between
two points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal
to the potential difference between two parallel, infinite planes
spaced 1 meter apart that create an electric field of 1 newton per
coulomb."

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

I'll probably get this wrong, But the volt is a derived unit.
We measure resistance (from the quantized hall effect.)
and time... from atomic transitions, and then define the charge of the
electron (I think) and from these get current and the volt follows.

George H.

Most everything is a derived unit.

The volt is now defined in terms of frequency, through a superconducting
Josephson junction.

Wiki says...

The kilogram is the only SI base unit with an SI prefix ("kilo", symbol
"k") as part of its name. It is also the only SI unit that is still
directly defined by an artifact rather than a fundamental physical
property that can be reproduced in different laboratories.

They're working on that -- http://www.nist.gov/pml/si-redef/kg_future.cfm

Inneresting stuff.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Bill Bowden · Feb 17, 2016

"George Herold" <gherold@teachspin.com> wrote in message
news:9cc6b69f-0d6d-46a1-9b4e-58efbefa5cd3@googlegroups.com...

On Monday, February 15, 2016 at 11:01:21 PM UTC-5, Bill Bowden wrote:
I see the voltaic pile produces a voltage of about 1 volt, but not
exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also 1
ohm. But I don't get the second part of 1 newton per coulomb across two
infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between two
points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal to
the potential difference between two parallel, infinite planes spaced 1
meter apart that create an electric field of 1 newton per coulomb."

I'll probably get this wrong, But the volt is a derived unit.
We measure resistance (from the quantized hall effect.)
and time... from atomic transitions, and then define the charge
of the electron (I think) and from these get current and the volt follows.

George H.

Yes, it's derived from newtons and meters and kilograms, but I can't figure
out where the long digits come from. Wiki says the elementary charge, the
charge of a proton (equivalently, the negative of the charge of an
electron), is approximately 1.6021766208(98)×10?19 . Seems like that could
be rounded off to exactly 1.6 x 10-18th for a standard value. Maybe a small
change to the meter or kilogram would make the numbers work out with less
digits? But I suppose that would screw up something else.

https://en.wikipedia.org/wiki/Coulomb

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

Jasen Betts · Feb 17, 2016

On 2016-02-16, whit3rd <whit3rd@gmail.com> wrote:

On Monday, February 15, 2016 at 8:41:59 PM UTC-8, John Larkin wrote:

If you charged a ball bearing with one coulomb of electrons, and
suspended it midway between two conductive planes that are 1 meter
apart and with a potential difference of 1 volt, the force on the ball
bearing would be 1 newton.

Of course, that ball bearing would have to be charged to about a
trillion volts. Maybe using one electron would be more practical.

Of course. One uses an electron instead, and observes the trajectory
in a cathode-ray tube with electrostatic deflection.

In 1909 Robert Millikan used a charged droplet of oil, and balanced it's
weight with the field

https://www.google.co.nz/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0ahUKEwij8oSptP7KAhUBzpQKHfP5CBEQFggpMAM&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FOil_drop_experiment&usg=AFQjCNFgw0bqTuz39VG6FO9lJ78Q33i8Tw&sig2=ydEKnVj-EXYxu2cKMIBqog

--
\_(ă)_

Tim Wescott · Feb 17, 2016

On Tue, 16 Feb 2016 19:02:37 -0800, Bill Bowden wrote:

"George Herold" <gherold@teachspin.com> wrote in message
news:9cc6b69f-0d6d-46a1-9b4e-58efbefa5cd3@googlegroups.com...
On Monday, February 15, 2016 at 11:01:21 PM UTC-5, Bill Bowden wrote:
I see the voltaic pile produces a voltage of about 1 volt, but not
exactly.
From this wiki article, a volt is 1 amp, at 1 watt, so it must be also
1 ohm. But I don't get the second part of 1 newton per coulomb across
two infinite planes spaced 1 meter apart. Can you clarify?

https://en.wikipedia.org/wiki/Volt

"One volt is defined as the difference in electric potential between
two points of a conducting wire when an electric current of one ampere
dissipates one watt of power between those points.[2] It is also equal
to the potential difference between two parallel, infinite planes
spaced 1 meter apart that create an electric field of 1 newton per
coulomb."

I'll probably get this wrong, But the volt is a derived unit.
We measure resistance (from the quantized hall effect.)
and time... from atomic transitions, and then define the charge of the
electron (I think) and from these get current and the volt follows.

George H.

Yes, it's derived from newtons and meters and kilograms, but I can't
figure out where the long digits come from. Wiki says the elementary
charge, the charge of a proton (equivalently, the negative of the charge
of an electron), is approximately 1.6021766208(98)Ă10?19 . Seems like
that could be rounded off to exactly 1.6 x 10-18th for a standard
value. Maybe a small change to the meter or kilogram would make the
numbers work out with less digits? But I suppose that would screw up
something else.

All the units are tied to various other things, so if you went to change
one thing then it'd change many, if not all, of the others.

There's a desire among physicists and metrologists to base everything on
Planck units (https://en.wikipedia.org/wiki/Planck_units) -- that way we
won't have units that are derived from, ultimately, anthropogenic
quantities.

Unless, of course, it turns out that the Planck units aren't as universal
as we think, and are just a product of our understanding at this time...

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

What is one volt?

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