Prepare for your exams
Get points
Guidelines and tips
Sell on Docsity
Docsity AI

Prepare for your exams

Study with the several resources on Docsity

Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips

Sell on Docsity

Docsity AI

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents

20 Points

For each uploaded document

Answer questions

5 Points

For each given answer (max 1 per day)

All the ways to get free points

Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Electrostatic Fields, Lecture notes of Physics

Effat University (EU)Physics

Notes of Electricity and Magnetism

Typology: Lecture notes

2017/2018

Uploaded on 10/21/2018

agandour 🇸🇦

(1)

6 documents

1 / 5

This page cannot be seen from the preview

Don't miss anything!

2/1/2016

Electric Fields

23.1 Properties of Electric Charges

•Electrostatic is the study of electric

charges which are not moving.

•Types of Charge: There are two types of electric

charges, arbitrarily called positive and negative.

•The net charge of a closed system never

changes.

•The net charge is found by adding the charges

arithmetically.

•Rubbing certain electrically neutral objects

together (the first material used was amber and

fabric), tends to cause these objects to attract or

repel small objects.

•These objects are said to be charged.

•If an object contains equal numbers of positive

and negative charges, it is electrically neutral.

•After separation, the negative charges and

positive charges are found to attract each other.

•On the other hand positive charges exert a

repulsive force on one another, the same as

negative charges. These results can be

summarized as : unlike charges attract and like

charges repel.

Discover Lecture notes of Physics Effat University (EU)

Partial preview of the text

Download Electrostatic Fields and more Lecture notes Physics in PDF only on Docsity!

Electric Fields

23.1 Properties of Electric Charges

• Electrostatic is the study of electric

charges which are not moving.

Types of Charge: There are two types of electric

charges, arbitrarily called positive and negative.

The net charge of a closed system never

changes.

The net charge is found by adding the charges

arithmetically.

Rubbing certain electrically neutral objects

together (the first material used was amber and

fabric), tends to cause these objects to attract or

repel small objects.

These objects are said to be charged.
If an object contains equal numbers of positive

and negative charges, it is electrically neutral.

After separation, the negative charges and

positive charges are found to attract each other.

On the other hand positive charges exert a

repulsive force on one another, the same as

negative charges. These results can be

summarized as : unlike charges attract and like

charges repel.

The net amount of electric charge produced in any

process is zero.

In other words: in any process, electric charge can

not be created or destroyed, however it can be

transferred from one object to another.

During the past century, the negative charges

have been shown to be carried by particles which

are now called electrons, while the positive

charge carriers are known as protons.

In 1909, Robert Millikan (1868 – 1953)

discovered that electric charge always occurs as

some integral multiple of a fundamental amount

charge e.

The charge carried by an electron is – e and the

charge carried by a proton is +e, where e is the

elementary charge.

e  1. 602  10 ^19 C

Electrons are bound to atoms and molecules, but

how tightly bound varies dramatically.

In some material, the electrons are free to move,

these are called conductors.

In other materials, the electrons are much more

tightly bound to the atoms or molecules, these are

called insulators.

Materials that are intermediate between

conductors and insulators are called

semiconductors.

Charging by Rubbing

Some insulating materials, when rubbed together, result in a net charge on each object.

23.3 Coulomb’s Law

States that two point charges exert a force F on one another, that is 23.3 Coulomb’s Law
States that two point charges exert a force F on one another, that is
States that two point charges exert a force F on one

another, that is

2 2 9 2 1 2 2 1 2

C

N m

k

r

q q

F k

r

F

F qq

e e e e

This value of k is valid only in vacuum.
is the permittivity of free space.



ke 

 0 2 2 12

0 8.^8510

Nm

C

k

  ^ 

  Example 23. The Hydrogen Atom

The electron and proton of a hydrogen atom are separated (on the average) by a distance of approximately 5. 3 × 10 −^11 m. Find the magnitude of the electric force and the gravitational force between the two particles.
𝑘𝑒 = 8. 99 × 109 N 𝑚^2 /𝐶^2 ,𝑒 = 1. 602 × 10 −^19 𝐶
𝐺 = 6. 67 × 10 −^11 𝑁 𝑚^2 /𝑘𝑔^2 , 𝑚𝑒 = 9. 11 × 10 −^31 𝑚𝑝 = 1. 67 × 10 −^27 Example 23. Find the Resultant Force
Consider three point charges located at the corners of a right triangle as shown in Figure 23.7, where 𝑞 1 = 𝑞 3 = 5. 00 𝜇𝐶, 𝑞 2 = − 2. 00 𝜇𝐶, and 𝑎 =

100 𝑚. Find the resultant force exerted on 𝑞 3. Example 23. Where is the Net Force Zero?

Three point charges lies along the 𝑥 axis as shown in Figure 23.8. The positive charge 𝑞 1 = 15. 0 𝜇𝐶 is at 𝑥 = 2. 00 𝑚, the positive charge 𝑞 2 = 6. 00 𝜇𝐶 is at the origin, and the net force acting on 𝑞 3 is zero. What is the 𝑥 coordinate of 𝑞 3. Example 23. Find the Charge on the Spheres
Two identical small charged spheres, each having a mass 3. 00 × 10 −^2 𝑘𝑔 , hang in equilibrium as shown in Figure 23.9a. The length 𝐿 of each string is 0. 150 𝑚, and the angle 𝜃 is 5. 00 °. Find the magnitude of the charge on each sphere.

Electrostatic Fields, Lecture notes of Physics

Related documents

Partial preview of the text

Download Electrostatic Fields and more Lecture notes Physics in PDF only on Docsity!

Electric Fields

23.1 Properties of Electric Charges

• Electrostatic is the study of electric

charges which are not moving.

charges, arbitrarily called positive and negative.

changes.

arithmetically.

together (the first material used was amber and

fabric), tends to cause these objects to attract or

repel small objects.

and negative charges, it is electrically neutral.

positive charges are found to attract each other.

repulsive force on one another, the same as

negative charges. These results can be

summarized as : unlike charges attract and like

charges repel.

process is zero.

not be created or destroyed, however it can be

transferred from one object to another.

have been shown to be carried by particles which

are now called electrons, while the positive

charge carriers are known as protons.

discovered that electric charge always occurs as

some integral multiple of a fundamental amount

charge e.

charge carried by a proton is +e, where e is the

elementary charge.

how tightly bound varies dramatically.

these are called conductors.

tightly bound to the atoms or molecules, these are

called insulators.

conductors and insulators are called

semiconductors.

another, that is

C

N m

k

r

q q

F k

r

F

F qq

ke 

0 8.^8510

Nm

C

k

  ^ 