Understanding Capacitance: Exploring the Relationship Between Charge and Voltage

In summary, the conversation touches on the concept of charge transfer between a battery and a piece of metal, as well as the relationship between capacitance and the distance between two metal plates. The speaker questions how capacitance can be applied in situations where the plates are infinitely far apart and the responder suggests that the issue lies in the assumption of an infinite distance between the plates. The responder explains that capacitance is based on the interaction between two objects in close proximity.
  • #1
daudaudaudau
302
0
Hi. I'm trying to understand a couple of things.

When you put a piece of metal on, say the cathode of a battery, I suppose there is a charge transfer from the battery to the metal because the electrons on the cathode have a high potential energy? And so if I connect a piece of metal to both the cathode and another one to the anode, one piece should receive electrons and the other one should lose electrons.

But I cannot make this fit with the capacitance formula Q=CV, because if the two metal pieces are infinitely far apart, C=0 and then no charge is induced at all.
 
Physics news on Phys.org
  • #2
Why do you want your plates to be infinitely far apart?
 
  • #3
I think the "infinitely far apart" portion of your thoughts is the problem, not Q = CV. How do you connect two plates infinitely far apart to the same battery? How do you expect two objects infinitely far apart of exert an influence each other? Capacitance arises because two objects near each other effect each others' ability to store charge.
 

FAQ: Understanding Capacitance: Exploring the Relationship Between Charge and Voltage

What is capacitance?

Capacitance is the ability of a body to store an electrical charge. It is measured in farads (F) and is determined by the geometry and material properties of the body.

How is capacitance related to charge and voltage?

The capacitance of a body is directly proportional to the amount of charge it can hold and inversely proportional to the voltage across it. This relationship is described by the formula C = Q/V, where C is capacitance, Q is charge, and V is voltage.

What is the role of dielectric materials in capacitance?

Dielectric materials are used in capacitors to increase their capacitance. These materials have a high permittivity, which allows them to store more charge for a given voltage. They also act as insulators, preventing the flow of current between the capacitor's plates.

How does capacitance affect the behavior of an electrical circuit?

Capacitance can affect the behavior of a circuit in several ways. It can act as a low-pass filter, allowing low-frequency signals to pass through while blocking high-frequency signals. It can also store energy and release it quickly, making it useful in applications such as camera flash circuits.

What factors affect the capacitance of a capacitor?

The capacitance of a capacitor is affected by several factors, including the distance between its plates, the area of its plates, and the type of dielectric material used. It also depends on the material properties of the plates, such as their conductivity and thickness.

Similar threads

B High voltage batteries and charge distribution
Replies
1
Views
326
Semiconductor physics: Voltage below forward voltage
Replies
4
Views
4K
B How is surface charge accumulated?
2
Replies
36
Views
4K
Mechanisms Involved When Charging a Battery
Replies
10
Views
693
B Basic questions regarding theory of electrical capacitance
Replies
11
Views
1K
How do we know the mass of an electron?
Replies
28
Views
3K
Voltage & Capacitance: LanguageNerd's Questions
Replies
7
Views
1K
What Happens to the Voltage Across a Capacitor When the Plates are Separated?
Replies
4
Views
1K
I don't understand capacitance
Replies
21
Views
5K
Basic question regarding applied voltage and circuits
Replies
10
Views
3K

Hot Threads

Recent Insights

Back
Top