Electric and Magnetic Fields Flashcards
Electric field
A region of space that will cause charged particles to experience a force
Electric field lines
Imaginary visualizations of the region of influence of an electric field
Electric field strength
The force to charge ratio for a charged particle experiencing a force due to an electric field
Potential
A measure of possible field energy in a given location within that field. Electric potential is the energy per unit charge at that location
Potential difference
The change in potential between two locations in a given field
Equipotentials
Positions within a field with zero potential difference between them
Capacitor
An electric circuit component that stores charge, and so can be used as an energy store
Capacitance
A measure of the capability of a capacitor; the amount of charge stored per unit voltage across the capacitor, measured in farads, F
Time constant
For a capacitor-resistor circuit, the product of the capacitance and the resistance, giving a measure of the rate for charging and discharging the capacitor. symbol is curvy tiny T
Exponential curves
Mathematical function generated by each value being proportional to the value of one variable as the index of a fixed base: f(x)=b^x
Magnetic field
A region of space that will cause a magnetic pole to feel a force
Magnetic flux
referring to magnetic field lines, measured in Webers, Wb
Magnetic flux density
The ratio of magnetic flux to the area it passes through, unit Tesla, T
Magnetic field strength
An alternative phrase for magnetic flux density
Flux linkage
The amount of magnetic flux interacting with a coil of wire
Motor effect
The phenomenon that a wire carrying a current, held within a magnetic field, will experience a force
Flemings left hand rule
a system for determining the direction of the force generated by the motor effect
Lenz’s law
The direction of an induced emf is such as to oppose the change that caused it
Faraday’s law
The induced emf is proportional to the rate of change of flux linkage
photoelectric effect
The phenomenon in which electrons are released from a metal surface as a result of its exposure to electromagnetic radiation
Thermionic emission
The phenomenon in which electrons are released from a metal surface as a result of its exposure to thermal energy
Cathode ray
A beam of electrons
