Why would voltage stay the same when a dielectric is introduced?

In summary, the question is asking for an explanation as to why the voltage remains the same across capacitor 3 in the given set-up, despite the increase in capacitance due to the presence of a dielectric material. The answer lies in the fact that while the capacitance does increase, it does so for all three capacitors, resulting in no change in the overall voltage.
  • #1
okgo
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I need an explanation for question 6. Why would voltage stay the same across capacitor 3?


The dielectric increases capacitance which is inversely related to voltage correct? The equation Q=CV says this. So shouldn't voltage decrease across capacitor 3?
 
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  • #2
How do you get the voltage of C3 in the original set-up? How does the dielectric change all capacitance?

ehild
 
  • #3
Yes the capacitance does increase but it does so for all three capacitors.Take another look at the question.


Hello ehild.You just beat me to it.
 

1. Why does voltage stay the same when a dielectric is introduced?

When a dielectric material is introduced into a circuit, it increases the capacitance of the circuit. This means that the charge on the plates of the capacitor will also increase. However, the voltage is defined as the potential difference between the plates of the capacitor. Since the charge on the plates and the distance between them both increase by the same amount, the voltage stays the same.

2. How does a dielectric affect the capacitance of a circuit?

A dielectric material, also known as an insulator, is inserted between the plates of a capacitor to increase the capacitance of the circuit. This is because the dielectric material has a higher permittivity, which allows it to store more charge compared to the vacuum or air between the plates. This results in a higher capacitance value and a lower voltage for the same amount of charge.

3. What happens to the electric field when a dielectric is introduced?

When a dielectric material is introduced between the plates of a capacitor, it decreases the electric field between the plates. This is because the electric field is directly proportional to the voltage, and since the voltage remains the same while the distance between the plates increases, the electric field decreases. This is known as the dielectric's ability to "shield" the electric field.

4. Why do some dielectric materials have a higher permittivity than others?

The permittivity of a material is a measure of how much charge it can store in an electric field. It is influenced by the material's molecular structure and its ability to polarize in the presence of an electric field. Materials with a higher number of polarizable molecules, such as water or ceramic, have a higher permittivity compared to materials with fewer polarizable molecules, like air or vacuum.

5. Can a dielectric material ever decrease the voltage in a circuit?

No, a dielectric material cannot decrease the voltage in a circuit. As mentioned earlier, the voltage is defined as the potential difference between the plates of a capacitor. Therefore, as long as the distance between the plates remains constant, the voltage will also remain constant. The only way to decrease the voltage is to either decrease the charge on the plates or increase the distance between them.

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