103F Methods of Producing EMF and Magnetism Flashcards
_____ is potential energy that is ready to do electrical work
Electromotive force (EMF)
Kinetic energy is
based on motion
Potential energy is
based on position
EMF is produced by
- Chemical reaction
- Heat
- Pressure
- Light
- Magnetism
- Electrostatics
Producing an EMF by adding heat is commonly done by heating the junction of 2 dissimilar metals and this is called
Seebeck Effect
Thermoelectric generator that change heat into electricity is
Thermocouple
The method of producing electricity from pressure of force is called
Piezoelectricity
Also means push-electricity
Alternator
- changes AC <-> DC
- changes Frequency
Generator
Creates Electricity
_____ generation is the least utilized electromotive force producing method
Electrostatic
Strength (low)
Cost (high)
When all of the _____ in a group of atoms align, the result is a magnetic domain
Magnetic moments
Left hand conductor rule
- Curve of Fingers = Direction of Force
- Direction of Thumb = Direction of Current
3 basic factors affect the strength of an electromagnet
- The amount of current in the coil
- The number of turns of wire in the coil
- The type of core within the coil
When other factors are kept constant, the strength of the magnetic field is directly proportional to the number of turns
T or F
True
_____ opposes changes in current and acts like resistance
Inductance
Symbol for inductance
L
The unit of inductance measurement is the
henry (H)
What happens when a conductor moves through magnetic flux?
It develops an EMF
What is the term for an electrical charge at rest?
Electrostatic
What electrical charge technology is the basis for a precipitation-type of air filter?
Electrostatic
Which of the following are required to form a magnetic domain?
Magnetic moments
A temporary magnet is a magnet with magnetic domains aligned only while they are subjected to a magnetizing force
T or F
True
What is magnetic flux?
The lines of force in and around the magnet
What is residual magnetism?
Magnetism that remains in a material after the magnetizing force is removed
What is inductance?
The property of an electrical circuit where a current change forces the rise of a voltage flowing in the reverse direction of the incoming voltage
What is self-induction?
The result of current flowing through a coil, creating magnetic fields around each wire in the coil and those magnetic fields in turn affecting the current flow in the adjacent wires
What is mutual induction?
occurs when a change of current in one circuit causes an induced voltage in another circuit nearby
