Electromagnetic induction Flashcards
What is electromagnetic induction?
- A process whereby a changing magnetic field induces emf in a conductor.
What is electromagnetism?
Electromagnetism is the branch of physics that deals with the study of the effects of electricity and magnetism and their dependence on each other.
What did Michael Faraday discover about electromagnetic induction?
Michael Faraday found that when a magnet was passed through a coil of wire, a voltage was induced in the wire.
What factors affect electromagnetic induction?
- Speed at which the coil, wire or magnet is moved: Increased speed increases induced voltage.
- Number of turns on the coil: More turns result in higher induced voltage.
- Strength of the magnetic field: Stronger magnetic fields increase induced voltage.
- Direction of movement: Reversing the movement reverses the direction of the induced current.
State Faraday’s second law of electromagnetic induction.
The magnitude of the induced EMF is proportional to the rate of change of the magnetic flux density.
State Faraday’s first law of electromagnetic induction.
The changing magnetic field linked with a conductor induces an electromotive force (EMF) in the conductor.
What is Lenz’s law?
Lenz’s law states that the direction of an induced current in a conductor by a changing magnetic flux is always such that its own magnetic field opposes the changing magnetic flux.
What is mutual induction?
Mutual induction is the property of a coil which affects or changes the current and voltage in a secondary coil when two coils are brought in proximity with each other.
What is the principle of mutual induction used for?
The principle of mutual induction is the main operating principle for generators, motors, and transformers.
What is self-induction?
- is a phenomenon where a changing electric current within a circuit induces an electromotive force (emf) in the same circuit.
How is self-inductance defined?
- Self-inductance is defined as the induction of a voltage in a current-carrying wire when the current in the wire itself is changing.
- The magnetic field created by a changing current in the circuit induces a voltage in the same circuit, making the voltage self-induced.
What happens when current starts to build up in a solenoid?
As the current increases, each turn of the solenoid produces a changing magnetic flux linked with the other turns. According to Faraday’s and Lenz’s laws, a back EMF is induced in the solenoid, opposing the forward EMF from the battery, an effect called self-induction.
Where is self-induction applied?
Self-induction is applied in autotransformers, such as those used in x-ray circuits.
What is an electric motor?
An electric motor is a device that converts electrical energy into mechanical energy. When an electric current passes through a conductor placed in a magnetic field, a force acts on the conductor, causing it to move and produce mechanical energy.
