Презентация к билингвальному уроку по физике в 8 классе на тему "Electric field. Электрическое поле"

ЭЛЕКТРИЧЕСКОЕ ПОЛЕ

Lesson objectives : explain physical meaning of “electric field”

Repeat the terms

• Collect the puzzle.
• Combine the faces of the triangles with the corresponding terms in Russian, English and physical quantities.

Соберите пазл.

Совместите грани треугольников с соответствующими терминами на русском, английском и обозначениям физических величин.

Repeat the terms

• Who correctly put the puzzles, he received such a figure.

• Кто правильно сложил пазлы, тот получил такую фигуру.

Discuss the following question

• What can you do to make a droplet fly?
• Что ты можешь сделать, чтобы заставить капельку летать?

Gravitational field produces force – gravitational force.

Electric field produces force that is electric force.

Electric field

• Any electrically charged object produces an electric field .
• Electric field is sometimes abbreviated as  E -field.
• Electric field lines start at positive charges and end at negative charges

Electric field strength

The electric field strength is defined as the ratio of the electrostatic force acting on a negligible small test charge at this point to the value of the test charge itself.

Charge in electric field

• Electrostatics force acting on charge q placed in electric field can be found using formula:

Millikan’s experiment

• In this experiment oil drops are charged in covered chamber.
• В этом эксперименте капли масла заряжаются в закрытой камере.
• Then, oil drops fall into uniform electric field where it could be suspended (gravity balanced with electric force). This experiment helped to find the charge of electron.
• Затем капли масла попадают в равномерное электрическое поле, где их можно подвесить (гравитация уравновешивается электрической силой). Этот эксперимент помог найти заряд электрона.

Опыт Милликена — опыт по измерению элементарного электрического заряда,

проведённый Робертом Милликеном и Харви Флетчером в 1909 году.

Electric field strength

• Electric field strength is a vector quantity.
• The electric field strength produced by a point charge q at a distance r from it can be found by the formula:

Electric field lines

PRINCIPLE OF SUPERPOSITION

• If at some point there are several electric field intensities from different charges, then the resulting electric field strength will be equal to the vector sum of all electric field intensities.

Read the text and insert the missing words

• 1 . Atom consists of 3 main particles: protons, neutrons, and ……………..
• 2. Positively charged object has more ……….. than ………...
• 3. Unlike (not same) ……….. attract each other.
• 4. ……………. charged object has more electrons than protons.
• 5. Like (same) ………. repel each other.
• 6. Law of conservation of charge states that charge can be transferred, but total charge is always ………... .
• 7. We can calculate …….. between charges using the Coulomb’s law.
• 8. The smallest charge in nature is called ………. charge and it is charge of one……….. . Proton has the same charge, but it is ………. .
• 9. Charges produce field around them. It is called ……… …….. .
• 10. ……… …….. produces force - electric force.
• 11. Most atoms are electrically ………………………. .
• 12. Like charges …………… each other. But unlike charges …………. each other.
• 13. An ………………………. can detect whether an object has charge.

Keywords:

constant, attract, electroscope, charges, negatively, electrons, force, electron, positive, elementary, electric field, neutral, repel, protons, е lectrons