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 happens when magnetic flux through a loop increases?
The induced magnetic field points in the opposite direction to the applied field.
What happens when magnetic flux through a loop decreases?
The induced magnetic field points in the same direction as the applied field.
What is the effect of a changing magnetic flux?
It induces an electromotive force (EMF) in a nearby conductor.
What causes an induced current?
An induced EMF in a closed circuit.
What is the effect of an induced current?
It creates its own magnetic field that opposes the change in the original magnetic flux.
What is the effect of moving a conductor through a magnetic field?
It induces a current in the conductor.
What is the difference between Faraday's Law and Lenz's Law?
Faraday's Law: Quantifies the induced EMF based on the rate of change of magnetic flux. | Lenz's Law: Determines the direction of the induced EMF, opposing the change in flux.
Compare increasing vs. decreasing flux regarding induced magnetic field.
Increasing Flux: Induced magnetic field points opposite to the applied field. | Decreasing Flux: Induced magnetic field points in the same direction as the applied field.
Compare primary and secondary coils in a transformer.
Primary Coil: Creates a changing magnetic flux when AC voltage is applied. | Secondary Coil: Experiences induced EMF due to changing flux from the primary coil.