What are the considerations for analyzing current through thin gold wires?

In summary, the conversation discusses the properties and behavior of thin gold wires when connected to a voltage source and conducting current. Factors such as heating, resistance, and potential for curling or deformation are considered. The community suggests calculating the wire's resistance and using standard formulas for current and power to determine the effects of heat. It is mentioned that gold is a good conductor and does not corrode or change when heated, but its resistivity may increase. The conversation concludes with the suggestion to consult online resources for more specific information about the properties of materials.
  • #1
Joshua L
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7
Hey all, I've been thinking of a couple scenarios that involve thin wires (ones that have their diameter in the order of 1 mm). Suppose a gold wire with length L and diameter D is suspended straight in room temperature air and connected to some voltage V. Thus, a current will pass through the wire.

What must one consider when trying to analyze the wire? For example, would the (relatively) thin wire heat up significantly? Or, would enough of that heat be dissipated into the surrounding air so that any temperature effects can be ignored? Could the wire curl up? deform? And are there any other effects I haven't considered?

I'm just trying to learn more about the nature of thin gold wires. Any input from the community will be greatly appreciated.
 
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  • #2
Joshua L said:
What must one consider when trying to analyze the wire? For example, would the (relatively) thin wire heat up significantly? Or, would enough of that heat be dissipated into the surrounding air so that any temperature effects can be ignored? Could the wire curl up? deform? And are there any other effects I haven't considered?
I'm just trying to learn more about the nature of thin gold wires. Any input from the community will be greatly appreciated.

well... you can vary the current to get many different effects ...it will get hotter as the current increases ... a 1 mm gold wire should be getting warm to touch at perhaps 10A ... melt at perhaps 100A ..as for 'curling up ' I don't see why it should do that ...

gold is the second best conductor , (silver the best) ... neither oxidise or change on heating ...copper will oxidise .
 
  • #3
Joshua L said:
What must one consider when trying to analyze the wire? For example, would the (relatively) thin wire heat up significantly? Or, would enough of that heat be dissipated into the surrounding air so that any temperature effects can be ignored? Could the wire curl up? deform? And are there any other effects I haven't considered?
You need to know the resistance of the wire. You can calculate that from a property called the resistivity; googling for "resistivity electrical" will find the necessary formulas and lists of the resistivity of various substances including gold. Generally, resistance increases as wire is made the longer and thinner.

Once you know the resistance, the standard formulas for current and power (##V=IR##, ##P=I^2R##) will tell you how much current is flowing through the wire and how much heat it must dissipate. How the wire reacts to that heat depends on the how thin the wire is and how much voltage you're applying... But if you place a wire 1mm in diameter between the terminals of an ordinary 12 volt lead-acid automobile battery, it will quickly become glowing hot, burn, melt, and spatter little bits of molten metal in every direction. In fact, that's how fuses work - we deliberately place a length of thin wire in series in the circuit, so that it will melt and open the circuit if there is a short to ground.
 
  • #4
oz93666 said:
gold is the second best conductor , (silver the best) ... neither oxidise or change on heating

Thanks for replying, but what do you mean that gold doesn't change on heating? Do you mean its conduction? And does such a property remain unchanged for only low-temperature differences, or for even high temperatures?
 
  • #5
You'll have to be more specific if you want more specific answers. How much heat are you talking about? Even solid steel will melt to liquid and then boil into vapor if it is hot enough.
 
  • #6
Joshua L said:
…what do you mean that gold doesn't change on heating?
Gold doesn’t corrode or oxidize when heated, but its resistivity does go up.
 
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  • #7
Joshua L said:
Thanks for replying, but what do you mean that gold doesn't change on heating? Do you mean its conduction? And does such a property remain unchanged for only low-temperature differences, or for even high temperatures?
Have you thought of looking at one of the many lists of materials and their properties that are all over the Internet? Your eyes can do a better job of getting the information you want than a Q and A session on PF.
 

1. What is the definition of current through thin wires?

Current through thin wires refers to the flow of electric charge through a thin wire, typically measured in amperes (A). It is a measure of the rate at which electric charges move through a conductor, such as a wire.

2. How is current through thin wires measured?

Current through thin wires can be measured using an ammeter, which is a device that measures the flow of electric current in a circuit. The ammeter is connected in series with the wire, and the current can be read from the ammeter's display.

3. What factors can affect the current through thin wires?

The current through thin wires can be affected by the wire's resistance, the voltage applied to the wire, and the length and thickness of the wire. Other factors such as temperature and material composition can also play a role in determining the current.

4. What is the relationship between current and voltage in thin wires?

The current through thin wires is directly proportional to the voltage applied to the wire, according to Ohm's Law. This means that as the voltage increases, the current will also increase, and vice versa. However, the wire's resistance can also affect this relationship.

5. Why is the current through thin wires important?

The current through thin wires is important because it allows us to power electrical devices and transmit electricity over long distances. It also plays a crucial role in understanding and analyzing electrical circuits and their components.

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