Electrodynamics Flashcards
Faraday’s law:
The emf induced is directly proportional to the rate of change of magnetic flux (flux
linkage).
AC
Alternating current. Current which reverses direction periodically.
Conventional current:
The rate of flow of positive charge from the positive terminal of the cell to
the negative terminal.
DC
Direct current. Current flowing in one direction only.
Electromagnetic induction:
Occurs when a current is induced in a closed conducting loop when
there is a change in the magnetic flux passing through the surface
area of the conducting loop.
induced EMF
The total amount of electrical energy supplied per unit positive charge.
Magnetic fields
Produced by magnets or by moving electrical charges. Magnetic field lines
are drawn to represent the direction of the magnetic field at a point. The
symbol for magnetic field is B and its unit is the Tesla (T).
Magnetic flux density:
A representation of the magnitude and direction of the magnetic field.
Magnetic flux:
For a loop of area (A) in the presence of a uniform magnetic flux density (B), the
magnetic flux (Ф) passing through the loop is defined as Ф = BA cosθ, where θ is the
angle between the magnetic flux density (B) and the normal to the loop of the
area (A).
Magnetic flux linkage:
The product of the number of turns on a coil and the flux through a
coil (NФ).
Lenz’s law:
The induced current flows in a direction so as to set up a magnetic field to oppose
the change in magnetic flux.
Diode
A component that only allows current to flow in one direction.
Motor
A device which converts electrical energy into mechanical energy.
Generator
A device which converts mechanical energy into electrical energy.
