Electromagnetism Flashcards
Define Coulombs Law
states that like charges repel and opposite charges attract, with a force proportional to the product of the electric charges and inversely proportional to the square of the distance between them
Define electric fields
a region of space near an electrically charged particle or object within which a force would be exerted on other electrically charged particles
Define electric field strength
the intensity of an electric field at a particular location
Define electrical potential energy
the capacity of an electric charge to do work due to their position in an electric field
Define the term magnetic field
a region of space where a magnetic force is exerted
Which end does magnetic field lines flow from
North end of a magnet
What is a solenoid
a long straight coil of wired used to generate a controlled and almost uniform magnetic field
Define magnetic flux
a measure of the total magnetic field that passes through a given area; a measure of the number of magnetic field lines passing through the given area
Symbol: Φ
Units: Weber or Wb
Define magnetic flux intensity
the strength of a magnetic field or the number of magnetic field lines per unit area
Symbol: B
Units: Wb m^-2 or T
Define electromagnetic induction
the production of an electromotive force (EMF) or voltage across an electrical conductor due to its dynamic interaction with a magnetic field
Define EMF
a difference in potential that tends to give rise to an electric current
Units: V
Define Faraday’s Law
a law stating that when the magnetic flux linking a circuit changes, an EMF is induced in the circuit proportional to the rate of change of the flux linkage
Describe the process of inducing an EMF across a moving conductor in a magnetic field
Faraday’s law tells us that inducing a voltage into a conductor can be done by either passing it through a magnetic field, or by moving the magnetic field past the conductor and that if this conductor is part of a closed circuit, an electric current will flow
Define Lenz’s law
states that the direction of an induced current is such that it produces a current whose magnetic field opposes the change in the circuit or the magnetic field that produces it
Explain how transformers work in terms of Faradays Law and electromagnetic induction
Transformers contain a pair of windings, and they function by applying Faradays Law of induction. AC passes through the primary winding, which creates a varying magnetic flux. The magnetic field that results strikes the second winding and generates an AC voltage in that winding via electromagnetic induction.
