Matter, Energy And Electricity Flashcards
In simplest terms, what is Coulomb’s law?
That opposite charges attract. It is based off the distance between the 2 bodies, and their individual charges.
What are the subatomic particles and their charges?
Electron (-), Proton (+), Neutron (neutral)
In order, what are the 4 main conductors. From highest conductivity to lowest.
1) silver 2) copper 3) gold 4) aluminum
What is magnetism?
It is defined as the property of a material which enables it to attract pieces of iron.
What is reluctance?
The opposition that a material offers to the magnetic lines of force.
what are temporary magnets?
Materials that easily lose magnetic strength. These materials will also have a low reluctance.
What is residual magnetism?
The amount of magnetism which remains in a temporary magnet.
What is retentivity?
The ability to retain an amount of residual magnetism.
What is permeability?
The ease with which magnetic lines of force distribute themselves throughout the material.
Describe a magnetic lines of force path.
Emanate from the North Pole and enter the South Pole.
What is electromotive force? (EMF)
The difference potential between two bodies. Also called voltage.
What are the 6 methods for producing voltage?
Friction Pressure (piezoelectricity) Heat (thermoelectricity) Light (photo electricity) Chemical Action Magnetism
What is ohms law?
E (voltage) = I (current) x R (resistance)
Measured in Volts = Amperes x Ohms
What is resistance?
The opposition to current flow.
Resistance of a conductor is inversely proportional to its _____.
Cross sectional area.
Resistance of a conductor is directly proportional to its _____.
Length
What is Temperature Coefficient and state it’s different types.
TC: the amount of change of resistance per unit change in temperature.
Positive TC: higher temperatures increase resistance.
Negative TC: higher temperatures lower resistance.
What is Directed Drift?
An electron will be affected by an electrostatic field in the exact same manner as stated in Coulomb’s law.
Describe Effect of Directed Drift
A difference in potential across a conductor will attract electrons to the positive terminal of a batter. Each electron passed will leave an empty slot, creating a positive charge, there by attracting the next electron to flow.
What is the Left Hand Rule?
If current is flowing through a wire, and you were to grab it with your left hand, so that your thumb was pointing in the direction of flow, the Electro Magnetic Field will rotate in the direction your fingers are pointing.
How many valence electrons will a conductor, semi conductor and insulator contain?
Conductor: 3 or less
Semiconductor: 4
Insulators: 5 or more
