Tĩnh năng lượng điện là hiện tượng lạ mất thăng bằng điện tích trên bề mặt của một đồ liệu. Điện tích sẽ tiến hành lưu giữ lại ở đó cho đến khi nó rất có thể truyền đi vị trí khác thông qua một dòng năng lượng điện hoặc sự phóng điện.Bạn đã xem: Electric charge là gì
Static is generated when two objects made of different electrically neutral materials tương tác and then separate.Bạn đang xem: Electric charge là gì
1) tương tác between objects A và B
Electrically neutral objects A and B (with equal quantities of positive & negative charges)
2) Transfer of charge
When metals tương tác each other, electrons move from one with a smaller work function to lớn one with a larger work function. In other words, metal with a smaller work function will be charged positively & one with a larger work function negatively.Bạn đã xem: Electric charge là gì
3) Separation between objects A & B
Object A is charged negatively & object B positively.
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Figure 1. Static generation due to tương tác charging
Static is generated when two objects tương tác and then separate. The combination of the two objects may be solid và solid, solid và liquid, or liquid & liquid. Figure 2 shows examples.
Figure 2. Examples of static generation
All the above phenomena involve liên hệ between two objects and their separation.
Figure 3. Examples of charging
Friction between two objects in a triboelectric series causes the object in the upper position of the series to lớn be charged positively & that in the lower position lớn be charged negatively. Friction between two objects positioned far apart (C) also generates a larger amount of static than ones closer lớn each other (B) và much closer to each other (A) (A
When an object is charged
When an object is charged electrostatically, an electrical field is generated around the charged object, as illustrated in Figure 4.
Figure 4. Electrical field generated around charged objectsStarts from a positive electric charge & ends in a negative electric chargeLines vì not intersect each otherDoes not branch offThe electrical field is strong when lines of electric force are denseThe electrical field is uniform when lines of electric force are parallelComes out of (enters into) the surface of a conductor vertically
(a) Lines of electric force between objects with different electrical polarities
(b) Lines of electric force between objects with the same electrical polarity
Figure 5. Lines of electric force formed between two charged objects
E1: Strength of electrical field on a conductor surface
Density of lines of electric force: Low à Electrical field is weak
Charged conductive sphere A
E2: Strength of electrical field on a conductor surface
Density of lines of electric force: High à Electrical field is strong
Charged conductive sphere B
Figure 6. Lines of electric force from two charged conductors with different quantities of electric charge
What is electrostatic force (Coulomb force)?
Electrostatic force (Coulomb force) is the source of an electrostatic phenomenon. As Figure 7 shows, the direction of the force between two charged objects differs according to whether the objects have different electrical polarities or the same electrical polarity. Electrostatic force is an attractive force (a) when the polarities are different and a repulsive force (b) when the two objects have the same electrical polarity.
(a) Force between objects with different electrical polarities
(b) Force between objects with the same electrical polarity
Figure 7. Electrostatic force between two charged objects
As Formula (1) shows, the strength of the electrostatic force (Coulomb force) is proportional to the product of the quantities of the electric charge of the two charged objects and inversely proportional lớn the square of the distance between the two objects.
F ∝Q1・Q2/r2 ・・・・・・・・・・・・(1)
Electrostatic induction is also caused by electrostatic force
Figure 8. Electrostatic induction caused by electrostatic force
Electrostatic discharge is also caused by electrostatic force (Coulomb force)
Figure 9. Generation of electrostatic discharge caused by electrostatic force
The electrical field around the charged object causes the negative ions (electrons) therein to be accelerated by the electrostatic force (Coulomb force), thereby having kinetic energy (wv). When these negative ions strike gas molecules in the electrical field & the following formula is true,
Ionization energy of the gas molecules
electrons are sputtered from the gas molecules, resulting in generation of negative ions & positive ions. The gas molecules are ionized if the negative ions thus generated are subject to kích hoạt of the electrostatic force and the negative ions are accelerated in the electrical field with its kinetic energy meeting the condition expressed in formula (2) above. Repetition of this process results in generation of electrostatic discharge.
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Charge distribution of a conductor is also influenced by electrostatic force (Coulomb force)
Figure 10. Distribution of electric charges on a charged conductive sphere
(a) Conductor with surface potential distribution
(b) Electric charges that are distributed in a way that makes the conductor surface equipotential
Figure 11. Electric charges are distributed on a conductor surface in a way that makes the surface equipotential.