Magnetism and Electromagnetism Flashcards
How does a current carryin wire create a magnetic field
An electric current in a conducter produces a magnetic field around it
The larger the electric current, the stronger the magnetic field
The direction of the magnetic field depends on the direction of the current
What is a soft magnetic material
Magnetic material that loses its induced magnetism quickly
What is a hard magnetic material
Magnetic material that permanently keeps its induced magnetism
How do you do flemmings left hand rule
Using left hand, point first finger in direction of the field, second finger in direction of the current.
Your thumb will point in the direction of the force (motion)
How does a loudspeaker work because of the motor effect
A.C. Electrical signals from an amplifyer are fed to a coil of wire in the speaker which is wrapped around the base of a cone
The coil is surrounded by a permanent magnet, so the A.C. signals cause a force on the coil to make it move back and forth
These movements make the cone vibrate and this creates sound
What is electromagnetic induction?
The creation of a voltage in a wire which is experiencing a change in magnetic field
What is the dynamo effect?
Generating electricity using energy from kinetic energy stores
How do you get a bigger voltage in electromagnetic induction
Increase:
The strength of the magnet
The number of turns on the coil
The spped of movement
How does a simple generator work?
They rotate a coil in a magnetic field (
