Why does negative charge reduce the potential of a metal plate in a capacitor?

In summary: This reduces the potential of the plate A, which in turn increases its capacitance according to the relation c=q/v. Therefore, negative charge reduces the potential of A. In summary, when a positive charge is given to a metal plate, negative charge is induced on a nearby plate due to electrostatic induction. This negative charge reduces the potential of the plate, thus increasing its capacitance according to the relation c=q/v. This explains why negative charge reduces the potential of A.
  • #1
logearav
338
0
dear members,
when a positive charge is given to a metal plate say A, negative charge is induced on the nearby plate B(say) due to electrostatic induction. the presence of negative charge reduces the potential of the plate which increases the capacitance of A by the relation c=q/v. my question is why negative charge reduces the potential of A.
thanks in advance
 
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  • #2
logearav said:
dear members,
when a positive charge is given to a metal plate say A, negative charge is induced on the nearby plate B(say) due to electrostatic induction. the presence of negative charge reduces the potential of the plate which increases the capacitance of A by the relation c=q/v. my question is why negative charge reduces the potential of A.
thanks in advance

According to me, with the B plate negatively charged, the whole system (A & B) is something like a neutral object. Look, a neutral atom consists of protons (in the nucleus) and electrons.
In fact the potential between A and B is increased.
 
  • #3
Potential is simply "electron pressure". If you squeeze some electrons into a piece of metal, that repulsion is the pressure (potential) they are under. However, if you bring a positive charge near that piece of metal, that positive charge pulls the electrons toward some point on the object away from the lead wire attached to that object, reducing the force that would otherwise cause them to leave that object through the wire on the opposite side of the object.
 

1. What is the principle behind capacitors?

The principle of capacitors is based on the concept of storing electrical energy in an electric field. A capacitor consists of two conductive plates separated by an insulating material, also known as a dielectric. When a voltage difference is applied across the plates, an electric field is created, causing one plate to become positively charged and the other negatively charged. This separation of charges creates the potential to store electrical energy.

2. How do capacitors work?

Capacitors work by storing electrical energy in an electric field. When a voltage difference is applied to the capacitor, the electrons from one plate are attracted to the other plate, creating a flow of current. As the capacitor becomes fully charged, the flow of current stops. When the voltage is removed, the capacitor can release the stored energy back into the circuit.

3. What is the capacitance of a capacitor?

The capacitance of a capacitor is a measure of its ability to store electrical energy. It is determined by the physical characteristics of the capacitor, such as the surface area and distance between the plates, as well as the type of dielectric material used. Capacitance is measured in farads (F), with smaller capacitors typically having capacitance in microfarads (μF) or picofarads (pF).

4. How does the capacitance affect the performance of a capacitor?

The capacitance of a capacitor directly affects its ability to store electrical energy. A higher capacitance means that the capacitor can store more energy at a given voltage, while a lower capacitance means it can store less energy. Capacitance also affects the time it takes for a capacitor to charge and discharge, with higher capacitance resulting in a longer charging and discharging time.

5. What are some practical applications of capacitors?

Capacitors have a wide range of practical applications in various fields, including electronics, telecommunications, and power systems. They are commonly used in electronic circuits for filtering, timing, and energy storage. They are also used in power supplies to improve power factor and reduce voltage fluctuations. In telecommunications, capacitors are used in filters and amplifiers. Additionally, capacitors are used in energy storage systems for renewable energy sources, such as solar and wind power.

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