Mag Fields Flashcards
How can induced emf be increased?
Moving the wire faster
Using a stronger magnet
Make the wire into a coil and push the magnet in and out of the coil
What must be true for an emf to be induced in a wire
Wire must not be parallel to field lines, the wire must be perpendicular/cut across the magnetic field lines.
What is Lenz’s law
states that the direction of the induced current is always such as to oppose the change that created it.
What is Farraday’s Law
States that the induced emf in a circuit is equal to the rate of change of flux linkage through the entire circuit.
What things affect the magnitude of the induced emf?
Number of turns of wire
Area of coil
Strength of magnetic field
Frequency of rotation
What can increase efficiency of a transformer?
Laminated iron core
High restivity metal
Thick wire
Soft iron core
What is the difference between a step up and step down transformer?
A step up transformer increases the initial voltage by having more turns on the secondary coil than the primary. Step down transformer is vice versa.
