Electrodynamics Flashcards
Magnetic flux density
Is a representation of the magnitude and direction of the magnetic field.
Magnetic flux linkage
Product of the number of turns on the coil and the flux through the coil.
Faraday’s law of electromagnetic induction
The emf induced is directly proportional to the rate of change of magnetic flux (flux linkage)
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
AC: Alternating current
Current which reverses direction periodically.
Commutator:
A device which ensures that the direction of the current in a coil is reversed every half revolution.
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.
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).