connect 2 different wire gauge to pos and neg speaker terminal

@almarg,

AC transmission using wire conductors.

Al,

Could you please explain in more detail the relationship of the electromagnetic wave, that travels in the space outside of the conductor, (At near the speed of light), and the "current" that travels very slowly slightly vibrating back and forth at 60Hz in the conductor. From what I understand the movement of the current in the conductor is quite slow.... Correct?

The electromagnetic wave is caused by the applied source voltage and the "current", "charge", in the conductor? (Amount of current in the closed circuit determined by the resistance of the connected load. I = E/R)..... Correct?

Am I correct in saying you can’t have the electromagnetic wave without having current? Install an on/off switch in series in the circuit. Close the switch the current passes through the switch contacts through the load and back to source.... Correct?

The bigger the load, the more current in the conductor. The more current in the conductor the larger the electromagnet wave.... Correct? And of course the conductor, wire, must have a current, ampere rating, to safely carry the current in the wire so the wire will not overheat.

IF the wire is too small to handle the amount of current in the wire is it the current that causes the wire to overheat or is it the energy of the electromagnetic wave? Please explain in detail.

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Not to confuse things, if only a voltage, (potential), is present, an electromagnet field will exist outside of the conductor/s without there being current... Correct?

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I know it is the energy, from the electromagnetic wave, that makes a heating element heat up and gives off its’ heat into the surrounding air around it. It is not the "current" directly causing the resistance element to heat up.... Correct?

I know the amount of energy consumed,(in watts), by the resistance element is determined by the source voltage and the resistance, in ohms, of the resistance element. E / R = I and we know the current..... Correct?

The Fuse.....

E x I = P

E = voltage

I = Current, amps

P = power, energy, measured in, watts, VA

A fuse rated at 2 amps with a maximum voltage rating of 250V. herman said it is the energy of the electromagnetic wave passing on the outside of the fuse element link that causes it to melt and blow open when the fuse is overloaded.

OK

Isn’t the size, (for lack of a better word), of the electromagnetic wave energy determined by the applied source voltage and the current in a closed circuit? E x I = P. Is not P the energy of the electromagnetic wave?

So say the load is 150 watts and a 2 amp 250V fuse is used to protect the load. The FLA of the 150 watt load is, 150W/120V = 1.25 amps.

Here is where I get hung up. As you know a 2 amp 250V fuse can be used for any voltage 250V or less. It could be used where the voltage is 24V. The ampere rating of the fuse is still 2 amps. So to me the current has to be some component that causes the fuse to blow when the current that passes through the fuse link and exceeds 2 amps in the time curve set by the fuse manufacture. NOTE I did not say current flow.

WOW,... I know,..... I sure have a lot of questions on my mind. Blame herman.

Very best regards,

Jim

Hi Jim,

As always you ask good questions.  Regarding the first one, though...

Could you please explain in more detail the relationship of the electromagnetic wave, that travels in the space outside of the conductor, (At near the speed of light), and the "current" that travels very slowly slightly vibrating back and forth at 60Hz in the conductor.

... I'm not sure what I can add to what I said in my long post above dated 8-23-2017 at 7:08 p.m. EDT.

Regarding your other questions:

From what I understand the movement of the current in the conductor is quite slow.... Correct?

Correct, assuming "current" is defined as the movement of charge carriers (i.e., electrons in a metallic conductor).  An example described in the Wikipedia writeup on Drift Velocity indicates that for a current of 1 ampere in a copper conductor of 2 mm diameter the velocity calculates to 23 um/second  ("um" = millionths of a meter).  As noted in the writeup, btw, random movement of electrons even in the absence of "current" occurs at a far greater velocity (the Fermi velocity) than the "drift velocity" of current, although the Fermi velocity is still vastly slower than the speed of electromagnetic wave propagation. 

Am I correct in saying you can’t have the electromagnetic wave without having current?

Yes, in the case of electrical energy that is being conveyed via wires.  Electromagnetic waves can of course propagate in free space, as in the cases of radio waves and light waves.

The bigger the load, the more current in the conductor. The more current in the conductor the larger the electromagnet wave.... Correct?

Yes, assuming "larger" is interpreted in the sense of having "more energy."

IF the wire is too small to handle the amount of current in the wire is it the current that causes the wire to overheat or is it the energy of the electromagnetic wave? Please explain in detail.

The Poynting Vector, which describes the direction in which energy is being propagated, would be perfectly parallel to the conductor if the conductor's resistance were zero.  Since that resistance is non-zero, the Vector will tilt slightly toward the conductor, resulting in a small amount of energy being transferred into conductor, absorbed by its resistance, and converted to heat.  In effect, the resistance of the conductor causes it to become part of the load.

... if only a voltage, (potential), is present, an electromagnet field will exist outside of the conductor/s without there being current... Correct?

I'm not 100% certain, but I believe in that situation an electric field would be present, but not a magnetic field.

I know it is the energy, from the electromagnetic wave, that makes a heating element heat up and gives off its’ heat into the surrounding air around it. It is not the "current" directly causing the resistance element to heat up.... Correct?

As I've said, in the case of electrical signals (or power) being conducted via wires the electromagnetic wave and "the current" go hand-in-hand, and one would not exist without the other.  So the question is essentially just an academic/philosophical one IMO, not unlike the classical question of whether the chicken or the egg came first. 

Your succeeding statements involving E, I, P, etc. are of course correct.

herman said it is the energy of the electromagnetic wave passing on the outside of the fuse element link that causes it to melt and blow open when the fuse is overloaded.

It is energy absorbed **from** the electromagnetic wave by the non-zero resistance of the conductor in the fuse, which as I said causes the Poynting vector to tilt slightly toward the conductor, that causes it to blow.

Is not P the energy of the electromagnetic wave?

They are proportional, but strictly speaking energy corresponds to power x time.

Here is where I get hung up. As you know a 2 amp 250V fuse can be used for any voltage 250V or less. It could be used where the voltage is 24V. The ampere rating of the fuse is still 2 amps. So to me the current has to be some component that causes the fuse to blow when the current that passes through the fuse link and exceeds 2 amps in the time curve set by the fuse manufacture. NOTE I did not say current flow.

In my earlier long post I defined "the current" as follows:

What can be referred to as "the current," as opposed to "the signal," can be considered as corresponding to the number of electrons traversing a given cross-section of a conductor in a given amount of time. One ampere of current, for example, corresponds to one coulomb per second, where one coulomb corresponds to the amount of charge possessed by about 6.2 x 10^18 electrons.

Since the amount of energy that is absorbed from the electromagnetic wave by the conductor in the fuse and converted into heat (causing it to blow if excessive) is proportional to both the energy that is being conveyed by that wave and to "the current," it is reasonable (and of course far more practical) to analyze the situation in terms of amperes and ohms, rather than in terms of joules (a unit of energy) and Poynting Vectors.

And correspondingly, since in the case of electrical signals (or power) being conducted via wires the slow moving "current" and the very fast moving electromagnetic wave go hand-in-hand (as I've explained), IMO it would be meaningless to think of one but not the other as being the cause of the fuse blowing.

Best,

-- Al
  

Chalmersiv you should try it , you will be surprise on what you hear, I myself connected four different sets of cable, with different length, I have four systems, for me this system is the most live and dynamic of all my four systems..,maybe I got lucky, but it works.....

Al, (almarg),

Thank you for your responses to my questions.

... if only a voltage, (potential), is present, an electromagnet field will exist outside of the conductor/s without there being current... Correct?

I’m not 100% certain, but I believe in that situation an electric field would be present, but not a magnetic field.

I would agree, it is an electric field not a magnetic field.

.

Since the amount of energy that is absorbed from the electromagnetic wave by the conductor in the fuse and converted into heat (causing it to blow if excessive) is proportional to both the energy that is being conveyed by that wave and to "the current," it is reasonable (and of course far more practical) to analyze the situation in terms of amperes and ohms, rather than in terms of joules (a unit of energy) and Poynting Vectors.

And correspondingly, since in the case of electrical signals (or power) being conducted via wires the slow moving "current" and the very fast moving electromagnetic wave go hand-in-hand (as I’ve explained), IMO it would be meaningless to think of one but not the other as being the cause of the fuse blowing.

Your second paragraph has to be the logical case. And not just for the "why" the fuse blows.
The electrical energy will be greater at 120V than at 24V for a circuit using the same 2 amp fuse for overcurrent protection.

120V x 2A = 240 watts
24V x 2A = 48 watts

240V x 2A = 480 watts

Am I correct in assuming watts is a measurement of electrical energy?

Jim
.

Thanks, Jim. Regarding...

Am I correct in assuming watts is a measurement of electrical energy?

Watts is a unit of power, as you of course realize. Power is a quantity that is defined at a specific instant of time, although its average value over some interval of time can of course be calculated. Energy is defined as the product (multiplication) of power and time, and can be expressed as some number of joules, as well as in various other units.

The electrical energy will be greater at 120V than at 24V for a circuit using the same 2 amp fuse for overcurrent protection.

120V x 2A = 240 watts
24V x 2A = 48 watts

240V x 2A = 480 watts

The power and the energy being conveyed to the load will of course be much greater in the 120 and 240 volt cases than in the 24 volt case. But as I’m sure you realize but others may not, the only voltage that the fuse "knows about" is the one that appears between its two terminals, which when it is not blown corresponds to the amount of current it is conducting times its resistance. In the case of audio equipment operating normally that voltage will typically be a small fraction of a volt.

If and when the fuse were to blow, however, the full 120 volts would then appear across its terminals. Although no current would be conducted then since the resistance of the blown fuse would be essentially infinite.

Relevant to all of this, it’s worth noting that in the detailed specifications that are provided by the major fuse manufacturers, such as Littelfuse and Eaton/Cooper Bussmann, the "melting point" (i.e., the point at which the fuse is nominally rated to blow) is specified as i^2 x t (e.g., amperes squared x seconds). As you of course realize, power into a resistive load = i^2 x R, and i^2 x t is therefore proportional to energy.

Best regards,
-- Al