## Note on Electromagnetic Induction

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Whenever the magnetic flux linked with a closed circuit changes, an emf is induced in the circuit, called induced e.m.f. This phenomenon is called electromagnetic induction. The resulting current by electromagnetic induction is called induced current.

Faraday’s laws of electromagnetic induction or principle of electromagnetic induction

This law was propounded by an English physicist named Michael Faraday in 1831 AD. It is also called the principle of generators. It states that: -

1. Whenever the magnetic flux is linked with a closed circuit changes, an emf is induced in the circuit.
2. The induced e.m.f. lasts as long as the change in the magnetic flux continues in the circuit.
3. The magnitude of the induced e.m.f. is directly proportional to the rate of change of magnetic flux.

∴ Induced e.m.f. $$\propto$$ Rate of change of magnetic flux

#### Generator or dynamo

Electrical generators or dynamo are the machines used to convert mechanical energy into electrical energy. They are based on the principle of electromagnetic induction. A dynamo is used to induce current in fewer amounts and a generator is used to induce electric current in large scale.

It should be noted that the name generator is actually a misnomer, as no energy is being generated by it but is only converted from one form to another. A generator or dynamo converts kinetic energy into electrical energy.

• Whenever the magnetic flux linked with a closed circuit changes, an emf is induced in the circuit which is called induced e.m.f.
• The resulting current by electromagnetic induction is called induced current.
• Principle of electromagnetic induction was propounded by an English physicist named Michael Faraday in 1831 AD.
• Electrical generators or dynamo are the machines used to convert mechanical energy into electrical energy.They are based on the principle of electromagnetic induction.
• A dynamo is used to induce current in fewer amounts and a generator is used to induce electric current in large scale.
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### Very Short Questions

The phenomenon by which the electric current is produced in a conductor due to relative motion between the conductor and magnet is called electromagnetic induction. The current so produced by electromagnetic induction. The current so produced by electromagnetic induction is called induced current.
An appliance that produces electricity on the basis of this principle is dynamo and generator.

Faraday's laws of electromagnetic induction are: -

1. First law: Whenever the magnetic flux is linked with a closed circuit changes, an emf is produced.
2. Second law: The magnitude of the induced emf is directly proportional to the rate of change of magnetic flux.
3. Third law: The induced emf lasts as long as the change in the magnetic flux continues in the circuit.

Low voltage alternating current should be increased to high voltage in order to transmit the electricity for long distance.

Whenever the magnetic flux linked with a closed circuit changes, an emf is induced in the circuit, called induced e.m.f. This phenomenon is called electromagnetic induction.

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• ### Principle of electromagnetic induction was propounded by ______.

Stephen Hawking

William Mitchell

James watt

• ### Principle of electromagnetic induction is also called ______.

the principle of generators

the principle of electric motor

the principle of indicators

None

• ### Electrical generators or dynamo are the machines used to convert ______.

mechanical energy into electrical energy

electrical energy into thermal energy

tidal energy into mechanical energy

electrical energy into mechanical energy

• ### The resulting current by electromagnetic induction is called ______.

None

magnetic current

induced current

electric current

• ### Which one of them is kept in the magnetic field of a magnet of a bicycle dynamo?

A permanent magnet
A coil
Carbon brushes
Armature
• ## You scored /5

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##### What i magnetic flux?

What is magnetic flux?

##### Selena

Wire is not used while making electromagnet, why?

##### sapana

what are the difference between metallic conduction of electricity and magnetic conduction of electricity?