Сформулируйте вопросы на английском языке и дайте ответы на них. Чему равно ускорение частицы зарядаq и массы m в электрическом поле е?
What is the acceleration of particle equal to charge of q and the masses of m in the electric field of Е?
In accordance with the law of Coulomb electrostatic field created by a point charge Q at a distance r from it, is equal in absolute value:
This field is called Coulomb. In the Coulomb field vector direction depends on the sign of the charge Q: if Q> 0, then the vector is directed along the radius of the charge, if Q <0, the vector is directed to the charge.
In the present problem for the calculation of the formula can be applied field strength in the capacitors:
Here U - voltage between the capacitor plates, d - the distance between the plates.
The force with which the field acts on the charge calculated by the formula F = Eq. However, according to Newton's second law, we obtain an expression for the field with known charge, mass and acceleration: E = ma / q.
Сформулируйте вопросы на английском языке и дайте ответы на них. Что такое электрическое равновесие? Сформулируйте свойства проводников в состоянии равновесия.
What is the electrical equilibrium? Specify properties of conductors in equilibrium.
When there is no net motion of charge within a conductor, the conductor is in electrostatic equilibrium
A conductor in electrostatic equilibrium has the following properties:
1. The electric field is zero everywhere inside the conductor; no electric field can exist inside a conductor. However, this statement is true only if the conductor is in static equilibrium.
2. Any net charge on the conductor resides entirely on its surface.
3. The electric field just outside the conductor is perpendicular to its surface and has a magnitude where _ is the surface charge density at that point.
4. On an irregularly shaped conductor, the surface charge density is greatest where the radius of curvature of the surface is the smallest.
Сформулируйте вопросы на английском языке и дайте ответы на них. Что такое электрический ток? Дайте определение среднего электрического тока и мгновенного электрического тока.
What is electric current? Give definition to average electric current and moment meaning of the electric current.
Now consider a system of electric charges in motion.
Suppose that the charges are moving perpendicular to a surface of area A, as shown in Figure
(This area could be the cross-sectional area of a wire, for example)
The current is the rate at which charge flows through this surface.
If ΔQ is the amount of charge that passes through this area in a time interval Δt, the average current Iav is equal to the charge that passes through A per unit time:
We define the instantaneous current I as the differential limit of average current:
Сформулируйте вопросы на английском языке и дайте ответы на них. Что такое плотность тока в проводнике? Сформулируйте закон Ома.
What is the current density in the conductor? Specify Ohm's law.
The current density J in the conductor is defined as the current per unit area.
for
many materials (including most metals), the ratio of the current
density to the electric field is a constant σ that is independent of
the electric field producing the current.
Ohm's Law deals with the relationship between voltage and current in an ideal conductor. This relationship states that:
The potential difference (voltage) across an ideal conductor is proportional to the current through it.
The constant of proportionality is called the "resistance", R.
Ohm's Law is given by:
U = I R