Fields Flashcards
Capacitance
The ratio of charge stored in a capacitor to the potential difference between the two sides of the capacitor
Coulomb’s Law
The size of the force that acts between two point charges is proportional to the product of their charges and is inversely proportional to the square of their separation
Dielectric
An insulating material placed between capacitor plates that prevents charge from crossing between the plates, becomes polarized when the capacitor is charged, and changes the capacitance of the capacitor
Eddy current
A small closed loop of current within a conductor or magnet
Electric current
A region of space in which charged particles experience a force
Electric field lines
A way of representing an electric field in a diagram, lines point from positive to negative
Electric field strength
At a point, the electrostatic force experienced by a unit of positive charge in the field
Electric potential
At a point, the work done moving a unit of positive charge from infinity to that point
Electric potential difference
The work done moving a unit of positive charge between two points
Electromagnetic induction
When a current-carrying conductor moves relative to a magnetic field, an EMF is induced in the conductor
Electrostatic force
The force generated between charges due to Coulomb’s law
Equipotential
Planes of points where the electric potential is the same; no work is done moving along these lines
Faraday’s Law
The magnitude of the induced EMF is proportional to the rate of change of magnetic flux linkage
Fleming’s Left Hand Rule
Thumb = force, first = field, second = current in the motor effect
Frequency
The number of complete oscillations of the current or voltage in an AC circuit per second
Lamination
When a transformer’s core is made up of sets of layers to prevent eddy currents
Lenz’s Law
The direction of an induced current is such that it opposes the current that created it
Magnetic field
A region of space in which magnetic materials and moving electric currents feel a force
Magnetic flux
The magnetic field passing through a given area
Product of magnetic flux density and area
Magnetic flux density
The strength of a magnetic field, measured in Tesla (T)
Magnetic flux linkage
The magnetic flux of a coil found by the product of the magnetic flux and the number of turns of the coil
Motor effect
The force felt by a current-carrying wire in a magnetic field
Oscilloscope
A device used to monitor periodically time-changing quantities such as current or voltage in an AC circuit
Peak value
The maximum current or voltage in an AC circuit.
