- #1
Aafia
- 70
- 1
What is emf in the coil? As far as I know about emf is that it is potential difference between two terminals of a source but what if it is induced in coil by changing flux linkage. What exactly happen when emf is induced?
What is induced magnetic field?
- Thread starter Aafia
- Start date
In summary, EMF (electromotive force) is the potential difference between two terminals of a source. In the case of induced EMF in a coil, it can be defined as the line or closed loop integral of the electric field produced in the circuit. This electric field causes the free charges (electrons) to move and results in electric current flowing. EMF is often confused with voltage, which is the potential difference across the terminals of a battery or other power source when a current is flowing. It is important to understand the distinction between EMF and voltage, as they are not the same thing and can lead to confusion in discussions about electricity.
- #2
arpon
- 235
- 16
When there is EMF in a circuit, electric field is produced across the circuit. Due to this electric field, the free charges (electrons) move and electric current flows.
You can define emf between points ##A## and ##B## as
$$\int^A_B \vec E \cdot \vec{dl}$$
Here line integral of electric field ##E## is evaluated around the circuit from point ##A## to ##B##.
For induced emf, we will consider closed loop integral, i.e, $$\oint_C\vec E \cdot \vec{dl}$$
where ##\vec E## is electric field, ##\vec{dl}## is an infinitesimal line element on the loop (i.e, the coil) ##C##.
Have I answered your question?
You can define emf between points ##A## and ##B## as
$$\int^A_B \vec E \cdot \vec{dl}$$
Here line integral of electric field ##E## is evaluated around the circuit from point ##A## to ##B##.
For induced emf, we will consider closed loop integral, i.e, $$\oint_C\vec E \cdot \vec{dl}$$
where ##\vec E## is electric field, ##\vec{dl}## is an infinitesimal line element on the loop (i.e, the coil) ##C##.
Have I answered your question?
- #3
Aafia
- 70
- 1
Thank you for the reply!arpon said:
This is making sense to me. But does this electric field is produced across battery terminals because what my teacher told me is
"emf is the potential difference between positive and negative terminal of the battery"
- #4
arpon
- 235
- 16
I meant that electric field is produced in the circuit. Just look at this figure:Aafia said:
I have shown the direction of electric field. Please do not hesitate to ask if you have any further question.
- #5
davenn
Science Advisor
Gold Member
2023 Award
- 9,589
- 10,254
More correctly, the Voltage is the potential difference across the terminals of the battery or other PSUAafia said:
You cannot have a "force" unless something is moving ie. till the battery is connected to a circuit and the current starts to flow
to quote @sophiecentaur from another recent thread
Dave
1. What is an induced magnetic field?
An induced magnetic field is a magnetic field that is created in a material when it is placed in an external magnetic field. This external magnetic field can come from a permanent magnet or from an electric current. The induced magnetic field only exists as long as the external magnetic field is present.
2. How is an induced magnetic field created?
An induced magnetic field is created through a process called electromagnetic induction. This occurs when a conductor, such as a wire, moves through an external magnetic field. The movement of the conductor causes an electric current to flow, which in turn creates a magnetic field.
3. What is the difference between an induced magnetic field and a permanent magnetic field?
The main difference between an induced magnetic field and a permanent magnetic field is that an induced magnetic field is temporary and only exists when an external magnetic field is present. A permanent magnetic field, on the other hand, is created in materials that have their own magnetic properties and does not require an external source.
4. What are some examples of induced magnetic fields?
Some common examples of induced magnetic fields include the magnetic fields created in a generator, electric motors, and transformers. In these devices, the movement of conductors through an external magnetic field creates the induced magnetic field that is used to generate electricity or create mechanical motion.
5. How is induced magnetic field used in everyday life?
Induced magnetic fields have a wide range of practical applications in everyday life. They are used in generators to produce electricity, in electric motors to power appliances and vehicles, and in transformers to transfer electricity at different voltages. Induced magnetic fields are also used in magnetic levitation trains, MRI machines, and many other technologies.
Similar threads
-
Electromagnetism
-
Electromagnetism
-
Electromagnetism
-
Electromagnetism
-
Electromagnetism
-
Electromagnetism
-
Electromagnetism
-
Electromagnetism
-
Electromagnetism