Understanding Motor and Inductor Emf

In summary: Even if your English is not perfect, it is better to try and write in a clear and understandable way rather than using shortcuts and abbreviations. This will make it easier for others to help you.
  • #1
momomo_mo
25
0
In these two cases , emf will be induced in different way.
for motor: current +B-field-->Force-->Coil rotate-->change of magnetic flux-->emf inducedd in the coil
for inductor , when the switch suddenly openfrom closes switch, there are a sudden change of magnetic flux ,there emf will be induced

the thing I want to ask:
why when the coil is suddenly jammed and come to stop,there will not be any induced emf in this cases??
isn't it just the case of inductor,there are a change of magnetic flux
from many to none magnetic flux ?

why?

thank you
 
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  • #2
HeLPplease
 
  • #3
Usually people that answer to posted questions, try to write theirs answers clearly and in a correct language without stupid abbreviations, like "u" four "you". I think they deserve that you write your questions clearly, without shortcuts and in a text you could show to your English teacher.
Most people who answer your questions are not your pals. Some of them happen to be older than your actual teachers.
If your post had not been answered, it is not that no one is able to answer. It is just that no one is willing to decode your so badly written question.
 
  • #4
In the two examples given:
for motor: alternating current +B-field-->Force-->Coil rotate-->change of magnetic flux-->emf inducedd in the coil

for inductor , when the switch suddenly openfrom closes switch, there are a sudden change of magnetic flux ,there emf will be induced
The motor has an applied alternating current, and the time varying current induces a time varying magnetic field (which would otherwise by constant).

In the inductor, the closing of the switch allows a time varying current. A constant current would induced a constant B-field.

If an inductor is moving in a constant magnetic field and emf will be induced. If the inductor is not moving, i.e. stopped, then the field is constant (non-varying) and no emf is induced.

See principle of induction motor - http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indmot.html

Inductance concepts
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/induct.html
 
  • #5
SORRY
I think it will be easier for the readers to read my question by using flow chart.I apologized for my poor english because I usually weak in expressing my point of view in English.I used to write in Chinese.Really sorry.Sorry for all the readers.Sorry for my distrubance.
 
  • #6
You are welcome to post questions. Just try to write them clearly.
 

1. What is motor and inductor EMF?

Motor and inductor EMF (electromotive force) is the voltage generated by a motor or inductor due to the motion of charged particles within a magnetic field. It is also known as back EMF, as it opposes the applied voltage and limits the current flow in a circuit.

2. How is motor and inductor EMF calculated?

The magnitude of motor and inductor EMF is equal to the rate of change of magnetic flux through the circuit. It can be calculated using the equation EMF = -N(dΦ/dt), where N is the number of turns in the coil and dΦ/dt is the change in magnetic flux over time.

3. What is the purpose of understanding motor and inductor EMF?

Understanding motor and inductor EMF is essential for designing and analyzing electric motors and generators. It also helps in troubleshooting and improving motor efficiency, as well as predicting and preventing potential motor failures.

4. How does motor and inductor EMF affect the performance of a motor?

The magnitude of motor and inductor EMF is directly proportional to the speed of the motor and the applied voltage. As the motor speeds up, the back EMF also increases, which in turn limits the current flow and prevents the motor from burning out. However, if the applied voltage is too high, it can cause excessive back EMF and reduce the motor's torque.

5. Can motor and inductor EMF be controlled or manipulated?

Yes, motor and inductor EMF can be controlled and manipulated by changing the applied voltage or the number of turns in the coil. This is commonly used in motor control techniques, such as pulse-width modulation, to adjust the motor's speed and torque output.

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