![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
F = Mg + Ma how to calculate the acceleration of a and its derivation formula
ma=F-mg
a=F/m-g
How to deduce the formula of Hall voltage?
A: let the charge of the carrier be q, the average velocity of directional movement be V, and the magnetic induction be B. at equilibrium, Q * V * b = QE, e = V * B. let l be the width of the metal sheet, and the electric field be uniform. Then u = e * L = V * b * l, and the number of carriers per unit volume be n. according to the definition of current, I = n * Q * V * s, where s = L * D, is
How to deduce Hall coefficient in Hall element?
Let d be the thickness of the sheet, K be the hall coefficient, and a be the length of the plate,
Bqv=Uq/a
I=nqdav
U=BI/nqd=kBI/d
So, k = 1 / NQ
The derivation process of micro expression of current
I hope it's clear
I = q nsv
1: Current intensity in a section of conductor
q: Charge per charge
n: The number of free charges per unit volume
s: Cross sectional area of conductor
v: Directional moving rate of free charge in conductor
Because the current intensity is the unit time through the unit cross-sectional area of electricity
And the electric quantity can be expressed as the electric quantity of electric charge multiplied by the number of electric charges
So we can get the above formula
How does Hall voltage form?
Hall effect is essentially the deflection of a moving charged particle caused by Lorentz force in a magnetic field. When the charged particle (electron or hole) is confined in a solid material, the deflection will lead to the accumulation of positive and negative charges in the direction perpendicular to the current and magnetic field, thus forming an additional transverse electric field
The metal or semiconductor plate with current I is placed in a uniform magnetic field with magnetic induction intensity B. the direction of the magnetic field is perpendicular to the direction of the current, and the transverse potential difference u h appears between the third pair of surfaces of the metal plate, which is called Hall effect. U h is called Hall potential difference
The experimental results show that the Hall potential difference is directly proportional to the current I and the magnetic induction B, but inversely proportional to the thickness d of the plate,
What is the output signal, voltage or current of Hall voltage sensor? What is the relationship between it and input? What about Hall current sensor?
The output of Hall current sensor can be divided into two types: current type and voltage type, most of which are current type. The current type has strong anti-interference ability on site. The relationship between output and input depends on the specific sensor model, and there will be some information in the data, such as 5000A / 5V, 5000A / 500mA, 5000v / 5V, 5000A / 500mA, etc
In the circuit as shown in the figure, the resistance R, inductance coil L and capacitor C are connected to an AC power supply, and the indication of three identical AC ammeters is the same. If the voltage of the power supply is kept unchanged and the frequency is increased, the indication I1, I2 and I3 of the three ammeters are ()
A. I1=I2=I3B. I1＞I2＞I3C. I2＞I1＞I3D. I3＞I1＞I2
With the increase of the frequency of alternating current, the impedance (resistance) of the resistor element remains unchanged, the inductive reactance of the inductor element increases, and the capacitive reactance of the capacitor decreases. Therefore, according to Ohm's law, it can be concluded that the current through the resistor remains unchanged, the current through the capacitor increases, and the current through the inductor decreases. As the original currents are equal, I3 > I1 > I2 is selected
The instantaneous voltage, resistance and capacitance are known
In the circuit, the resistor and capacitor are connected in series, the instantaneous voltage is U0, the capacitance is C, and the resistance is R. how to calculate the instantaneous current seems to be done by using the dynamic differential equation,
I said it in the circuit. Check it. Sorry, I can't remember it clearly. It seems that the power of E is related to resistance and capacitance
If the expression of an alternating current and voltage is u = 20sin314t (V), its peak? Effective value? Period? Frequency?
Peak voltage um = 20 V, RMS voltage U = um / √ 2 = 0.707, um = 14.14 V, period T = 2 Π / ω = 2 × 3.14/314 = 0.02 s, frequency & # 402; = 1 / T = 100 Hz
What is the relationship between voltage instantaneous value and EMF peak value?
Em=_e
The voltage is a sine wave, and the value at any point of the sine wave is the instantaneous value of the voltage; when the sine wave reaches the top of the wave, it is the peak value of the voltage, and it can also be the peak value of the electromotive force
RELATED INFORMATIONS
- 1. In the formula F = ma, when the acceleration a is negative, is f also negative?
- 2. The following is a correct understanding of the expression f = ma of Newton's second law and its deformation formula () A. According to f = ma, the resultant force of an object is directly proportional to its mass and inversely proportional to its acceleration. B. according to M = FA, the mass of an object is directly proportional to its resultant force and inversely proportional to its acceleration. C. according to a = FM, the acceleration of an object is directly proportional to its force and inversely proportional to its mass From M = FA, the mass of an object can be obtained by measuring its acceleration and resultant force
- 3. Is it v = at or V = 1 / 2at? (v = V + at or V = V + 1 / 2at?) if it is v = at, what is x = VT + 1 / 2at ^ 2? How to push?
- 4. What does the electromagnetic formula F = QE mean?
- 5. What is a in F = ma? What does a mean when the rocket accelerates up?
- 6. What does f-mg = ma mean?
- 7. Why is f equal to ma
- 8. Under what circumstances f-f = ma. How to calculate the external force of f-f = ma
- 9. The pressure on the lower surface of the board is equal to the buoyancy f = f floating = 6N?
- 10. Why not use Archimedes principle to calculate the buoyancy of floating objects? The teacher said that when floating, f floating = g object can discharge liquid according to Archimedes principle. That is to say, the buoyancy has something to do with the volume of the immersed liquid. Isn't there part of the floating that is not completely submerged? How can we say that f floating = gravity? These two problems can be calculated in both aspects What kind of application is it? When and how to use it? What's the difference
- 11. What does f = ma mean?
- 12. Which of the two definitions of force, f = Ma; F = DP / DT, is accurate? The second one is used by default in special relativity. Why? From the derivation of F = DP / DT, when the direction of force is not consistent with the direction of initial velocity, there is a certain difference between the direction of acceleration and the direction of force, so f = ma is wrong, even if it is instantaneous. I mean in special relativity
- 13. What are Newton's three laws?
- 14. What are Newton's three laws?
- 15. What is the relationship between the speed of sound and the temperature of medium?
- 16. Please design an experiment to measure the speed of sound in water, Please design an experiment to measure the speed of sound in water. The requirements are: 1. Write down the method; 2. The known conditions to be known in advance in the experiment and the quantity to be measured in the experiment are expressed in letters; 3. The speed of sound in water is expressed in a formula
- 17. What is Newton's law of motion? The content of the three laws
- 18. Is calculus Newton's first invention of Leibniz? I heard that Leibniz came first, because Britain was more developed than Germany at that time, and backward Germany had to give in. Although there were many disputes in history, who was it?
- 19. The third power of the integral sign cos times x times DX
- 20. Expand f (x) = ln (1 + x) into McLaurin series