Unit 1-2 Flashcards
What are magnets?*
Materials that attract ferrous metals
What are ferrous metals?
Do they corrode?
Give an example
Metals that mostly contain Iron (Fe, Ferrous) and are magnetic
Little resistance to corrosion; corrode very easily
Steel and iron
What are non-ferrous metals?
Do they corrode?
Give an example
Metals that do not contain iron and have no magnetic attraction
More resistance to corrosion; do not corrode easily
Aluminum, aluminum alloy, & copper
Every magnet has how many poles?
What are they?
Which poles repel each other? Attract?
2 poles
North and south
Like poles repel
Unlike poles attract
What is the magnetic field?
Also known as…?*
Outside/inside the field, what direction does the magnetic field travel? Do they cross?
(think about the paper with iron shavings)
Invisible line of force
Flux
Outside: arcs from north to south
Inside: lines from south to north
Never across each other
What are the two types of magnets?*
Permanent
Temporary (electromagnet)
What is a permanent magnet?*
Give an example
A magnet that maintains an almost constant magnetic field
Earth
What is a temporary magnet?*
Give an example
The magnetic field changes under certain circumstances
Electromagnets (large junkyard magnets)
Some ferrous metal (magnetizing a screwdriver with a permanent magnet)
What is electromagnetism?
What is this common on?* (provide examples)
The process of producing a magnetic field using an electric current (current producing field)
Very common on aircraft
relays/solenoids/motors (temporary magnets)
magneto and compass (permanent magnets)
What are the three factors of electromagnetism?
What do they determine?
Direction of current flow- determines the polarity of the magnetic field (N/S)
Strength of the electrical current- determines the strength of the magnetic field
Number of turns (wraps) of the coil- determines the strength of the magnetic field
How can we change the strength of an electromagnet?*
More current = stronger field
More turns = more magnetic flux
What are the two different theories on the current direction?
Which does the FAA use?
Convention Theory
Electron Theory
Electron Theory
What is the electron theory?*
Negative source is abundance of charge
Positive source is lack of charge
Current direction – negative to positive
How do you identify magnetic field direction for the electron theory?*
Left hand rule
Using the left hand rule, what does each finger represent?
Thumb – current direction
Wrapped fingers – direction of the magnetic field
The left hand rule applies to each _____ in the _____.*
Each _____ creates a _____ _____.*
The _____ from the previous _____ pushes the _____ _____ along the coil, _____ its strength.*
twist
coil
twist
magnetic field
current
twist
magnetic field
increasing
Relays and solenoids are _____.
electromagnets
Describe a relay (core/strength)
A fixed core (magnet)
Low strength
Describe a solenoid (core/strength)
A movable core (magnet) when electrified
High strength
S.M.H.: Solenoid. Moveable core. High strength.
What is induction?
The transfer of electric energy without direct electrical connections
ex. wireless phone charger
What is the left hand rule for generators?*
What does each finger represent?*
Finger gun with middle finger creating a right angle with pointer finger
Thumb - direction of force
Pointer - magnetic field
Middle - direction of current
(May be given 2/3, what is the other?)
Almost all voltage/current is produced using the process of _____ _____.
electromagnetic induction
What are the three elements of electromagnetic induction?*
Magnetic field
Conductor
Motion between the magnetic field & conductor
What are the three determining factors of produced voltage/current?*
Strength of the magnetic field
Number of coils (turns) of the conductor
Speed of motion between the magnet & the coil
