All Flashcards
How do generators convert mechanical energy into electrical energy?
A rotating coil in a magnetic field induces an emf and current in the coil.
How do transformers change the voltage of alternating current?
A primary coil creates a changing magnetic flux, which induces an emf in the secondary coil. The ratio of turns in the coils determines the voltage change.
Explain how magnetic braking works.
A moving conductor in a magnetic field experiences a force opposing its motion. Induced currents dissipate kinetic energy as heat, slowing down the object.
Describe the process of induction in induction cooktops.
Alternating current in a coil induces eddy currents in metal cookware, generating heat.
What is the first step to determine the direction of induced current?
Determine whether the magnetic flux is increasing or decreasing.
What is the second step to determine the direction of induced current?
Use Lenz's Law to determine the direction of the induced magnetic field.
What are the differences between generators and transformers?
Generators: Convert mechanical energy to electrical energy. | Transformers: Change the voltage of alternating current.
Compare increasing vs. decreasing magnetic flux regarding induced magnetic field direction.
Increasing Flux: Induced field opposes the applied field. | Decreasing Flux: Induced field is in the same direction as the applied field.
What happens when magnetic flux through a loop increases?
An induced current is generated, creating a magnetic field opposing the increase.
What is the effect of moving a conductor through a magnetic field?
An electromotive force (EMF) is induced in the conductor.
What is the effect of a changing magnetic field near a conductor?
It induces a voltage (EMF) in the conductor.
What happens when the magnetic flux is decreasing?
The induced magnetic field points in the same direction as the applied field.
What happens when a conductor moves through a magnetic field in magnetic braking?
Induced currents dissipate kinetic energy as heat, slowing down the object.