Understanding Static Charges & Electric Circuits: Evidence-Based Explanation

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Static charges generated by rubbing materials like glass with silk or rubber with cat fur result from the uneven transfer of electrons due to friction, creating a net positive charge on one object and a net negative charge on the other. In contrast, electric currents in wires from a battery consist solely of free-flowing electrons, with positive charges remaining stationary. Static charges are confined to the surface of objects and dissipate quickly, while electric currents are sustained as long as the power source is connected. The potential difference in static charges can be high but is typically short-lived, whereas electric circuits maintain a controlled potential difference over time. Thus, there is a clear distinction between static charges and the charges flowing in electric circuits.
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Is there any difference between the static charges generated by rubbing a glass rod with silk or a rubber rod with cat fur and the charges that flow (from a battery) through wires in an electric circuit? Give evidence for your answer.
 
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I'm not sure I'm the best person to answer this question, hopefully someone with more knowledge will come in and offer a more detailed answer, but for the mean time,

The charges that develop from the glass/silk & plastic/fur systems are generated from the breaking of the molecules when you rub the two together. ie: when you rub fur on plastic, the molecules in the fibers of the fur split un-evenly, and part of it is left with a net positive charge, and the other is left with a net negative charge (most of the negative pieces stick to the plastic, while most of the positive parts stick to the fur) . For the glass/silk scenario, I'm not sure if its the glass molecules or silk molecules that break, but a similar situation occurs.

The charged partics that make up the current in the wires between a battery are solely electrons, not broken molecules. (The positive charges ( or nucleons ) do not move).
 
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Yes, there is a difference between the static charges generated by rubbing a glass rod with silk or a rubber rod with cat fur and the charges that flow through wires in an electric circuit from a battery.

Static charges are caused by the transfer of electrons between two objects, resulting in one object having an excess of electrons (negative charge) and the other having a deficit of electrons (positive charge). This transfer of electrons occurs through the process of friction, where the two objects rub against each other.

On the other hand, charges that flow through wires in an electric circuit are caused by the flow of free electrons, which are already present in the material. This flow of electrons is known as an electric current and is driven by a potential difference, or voltage, created by a battery or other power source.

One evidence for this difference is the nature of the charges themselves. In static charges, the excess or deficit of electrons is confined to the surface of the object and does not move. In contrast, in an electric circuit, the charges are free to move through the wires.

Another evidence is the behavior of these charges. Static charges tend to dissipate quickly, as the excess or deficit of electrons seeks to neutralize itself. However, in an electric circuit, the flow of charges is sustained as long as the power source is connected.

Furthermore, the strength of the charges also differs. Static charges can reach high levels of potential difference, but they are usually short-lived. In an electric circuit, the potential difference is controlled by the power source and can be sustained for a longer period of time.

In conclusion, while both static charges and electric circuits involve the movement of charges, the underlying mechanisms and behaviors are different. Static charges are a result of friction between two objects, while electric circuits involve the flow of electrons through a power source. Therefore, there is a clear distinction between the two.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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