Electric motor and generator

Содержание и основные понятия

The current conductor in the magnetic field is powered by force. In the engine, it creates a torque, and in the generator, the conductor's motion in the field creates an electric current.
GEF · Grade 8
PIF · Baseline
Interactive model
Amper's power
electric motor
Generator
manifold
01
The physical picture
What happens and what boundaries the model has.
Main message
The current conductor in the magnetic field is powered by force. In the engine, it creates a torque, and in the generator, the conductor's motion in the field creates an electric current.
The direction of force depends on the direction of current and magnetic field.
The collector in the simple engine changes the current so that the moment stays in the direction.
The engine and generator are based on reversible electromagnetic processes, but convert energy in opposite directions.
How to reason
First, name the system and the interaction, then select the values, and only then write down the law. The formula works within the model's assumptions.
02
Laws and values
Symbols should be read as a relationship of values, not as a recipe for substitution.
F
∼
B
I
l
F\sim BIl
F
∼
B
I
l
Force per conductor
η
=
P
пол
P
затр
\eta=\frac{P_{\text{пол}}}{P_{\text{затр}}}
η
=
P
morning
​
P
Gender
​
​
Car SAP
Review of the situation
In the fan, electrical energy turns into rotor rotation, and in the cycle generator, wheel rotation creates the current for the lamp.
04
Links and application
In the real world
In the fan, electrical energy turns into rotor rotation, and in the cycle generator, wheel rotation creates the current for the lamp.
Model verification
Compare the prediction with observation, evaluate the units, the order of magnitude and the influence of the factors not taken into account. Disparity does not always mean an error of law: often idealization is no longer sufficient.
C
What needs to be understood
Outcome 1
Explain the physical meaning of the subject "Elector and Generator" through the model, not just the formula.
Outcome 2
Use the terms: Amper's power, electric motor, generator.
Outcome 3
Indicate the conditions for the applicability of the law, verify units and limit cases.
T
Terms of the topic
The definition should indicate the physical meaning, not a substitute for a domestic synonym.
Amper's power
Power from magnetic field to current conductor.
electric motor
A device that converts electrical energy into mechanical work.
Generator
A device that converts mechanical or other energy into electrical energy.
manifold
An electrical machine hub that switches a rotating wrapping connection with an external circuit.
F
Origin and conclusion of the formulas
The fundamental law cannot be "proven" by algebras: for each record, it is stated whether it is a definition, an experimental law, or a model effect.
F
∼
B
I
l
F\sim BIl
F
∼
B
I
l
empirical law
Power to guide.
The following is an indication of the definition, experience or law from which this entry arises and where it is applicable.
F
∼
I
F\sim I
F
∼
I
Amper's experience puts more power on the conductor when the current increases.
F
∼
B
,
F
∼
l
F\sim B,\qquad F\sim l
F
∼
B
,
F
∼
l
At perpendicular position, force is also proportional to field induction and active conductor length.
F
∼
B
I
l
F\sim BIl
F
∼
B
I
l
The combined quality entry does not include the angular multiplier and the ratio of the units selected.
Conditions:
The direct area with current is in a homogeneous magnetic field and perpendicular to line B; an arbitrary angle requires a sine α multiplier.
Monitoring:
The proportionality shall be verified; the dimension of full equality shall restore the factor omitted.
η
=
P
пол
P
затр
\eta=\frac{P_{\text{пол}}}{P_{\text{затр}}}
η
=
P
morning
​
P
Gender
​
​
definition
The car's cd.
The following is an indication of the definition, experience or law from which this entry arises and where it is applicable.
η
=
E
пол
E
затр
\eta=\frac{E_{\text{пол}}}{E_{\text{затр}}}
η
=
E
morning
​
E
Gender
​
​
The PAC is introduced as a share of the energy used that has become useful.
E
пол
=
P
пол
t
,
E
затр
=
P
затр
t
E_{\text{пол}}=P_{\text{пол}}t,\qquad E_{\text{затр}}=P_{\text{затр}}t
E
Gender
​
=
P
Gender
​
t
,
E
morning
​
=
P
morning
​
t
In the same energy interval, the corresponding average capacity multiplied by time is equal.
η
=
P
пол
P
затр
\eta=\frac{P_{\text{пол}}}{P_{\text{затр}}}
η
=
P
morning
​
P
Gender
​
​
The overall interval is reduced, so the AAC can be found in relation to capacity.
Conditions:
Useful and used power is averaged over one interval in steady state mode; Pzatre > 0, for per cent the result is multiplied by 100 per cent.
Monitoring:
The dimensions of both parts shall coincide; the result shall be checked for sign, order and limit case.
!
Model boundaries and typical errors
Error: Forget model condition
The key condition of this subject is that the direction of power depends on the direction the current and magnetic field are.
How to Check the Mind
The collection in the simple engine changes the current so that the moment retains the direction. Then check the units, vector direction and result behaviour at zero or very large parameter.
Σ
Conclusion on the topic
Electric motor and generator
The current conductor in the magnetic field is powered by force. In the engine, it creates a torque, and in the generator, the conductor's motion in the field creates an electric current.
The direction of force depends on the direction of current and magnetic field.
The collector in the simple engine changes the current so that the moment stays in the direction.
Any numerical result shall be accompanied by a unit, a sign and an explanation of its physical meaning.
The content is consistent with the FRP on Physics of the OS/OSS 2025 and the subject matter of the current lines of the PNP: I. M. Peryškin and co-authors (7–9), G. J. Mäkishev and coauthors (10–11), and with the lines "Engineers of the Future" and V. A. Kasyanov. The original texts are not reproduced, the text of the textbooks is not reproduced.