Confusion about how electric charge is transferred

In summary: Charge piles up if the rate of current flowing in is NOT equal to the rate of current flowing out.In summary, there is no net change in the number of electrons in a closed, isolated circuit, which explains why there can be a transfer of charges without any net gain or loss of electrons. This can be seen in examples such as a capacitor in a circuit or rubbing a balloon to charge it. However, charge can still accumulate if the rate of current flowing in is not equal to the rate of current flowing out.
  • #1
intelli78
1
0
I have a question about transfer of electric charge in metals. My understanding is that electrons move in and out of an object at an equal rate when current is flowing (i.e., net change in # of electrons is zero). At the same time, it is possible for an object to become positively or negatively charged by gaining or losing electrons.

These two facts seem contradictory to me; if there is no net change in # of electrons, how can any charge be acquired at all? What am I misunderstanding? Thanks.
 
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  • #2
In a closed, isolated circuit, current is the same throughout the circuit, so there is never any net gain or loss of charge. However, you can charge an object because the object is not isolated.

A good example is a capacitor in a circuit. Overall, the circuit is isolated. However, within the circuit the capacitor is not isolated because it is electrically connected to the rest of the circuit, and applying a voltage will cause charges to move off of one plate and onto the other, charging them. The plates are charged, but the net charge of the circuit is still neutral.

Another example is rubbing a balloon to charge it. Current flows to or from the balloon to whatever it is rubbed against, charging both objects. This is okay because neither of the objects are electrically isolated from each other, just like the plates of the capacitor.

I hope that makes sense.
 
  • #3
Charge piles up if the rate of current flowing in is NOT equal to the rate of current flowing out.
 

1. How is electric charge transferred?

Electric charge is transferred through the movement of charged particles, such as electrons or protons. In most cases, electric charge is transferred through the flow of electrons, which occurs when a material with an excess of electrons comes into contact with a material with a deficit of electrons. The electrons will then flow from the material with the excess towards the material with the deficit, creating a transfer of electric charge.

2. What is the difference between conductors and insulators in terms of electric charge transfer?

Conductors are materials that allow electric charge to flow easily, as they have a high number of mobile electrons. This means that they can easily transfer electric charge. Insulators, on the other hand, have a low number of mobile electrons and do not allow electric charge to flow as easily. This is why they are used to insulate and protect conductors in electrical circuits.

3. Can electric charge be transferred through a vacuum?

Yes, electric charge can be transferred through a vacuum, as long as there is a difference in electric potential between two points. This is known as electric discharge and is the principle behind phenomena such as lightning and electric arcs.

4. How does static electricity occur?

Static electricity occurs when there is a buildup of electric charge on the surface of an object. This can happen when two objects rub against each other, causing a transfer of electrons. The object that gains electrons becomes negatively charged, while the object that loses electrons becomes positively charged. The buildup of this charge can then lead to static electricity, which can be observed through effects such as sparks or hair standing on end.

5. Can electric charge be created or destroyed?

No, electric charge cannot be created or destroyed, it can only be transferred from one object to another. This is known as the law of conservation of charge, which states that the total amount of electric charge in a closed system remains constant. This means that if one object gains electrons, another object must lose an equal amount of electrons, resulting in no net change in the total amount of electric charge.

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