⚡️ Flashcards
What are the 7 fundamental and 2 supplementary units used in the SI standard
Fundamental
1. Length
2. Mass
3. Time
4. Electrical current
5. Temperature
6. Luminous Intensity
7. Amount of Substance
Supplementary units
1. Plane angle
2. Solid Angle
What are the electrical quantities (11)
- Capacitance
- Charge
- Conductance
- Energy (work)
- Frequency
- Impedance
- Inductance
- Power
- Reactance
- Resistance
- Voltage
What are the magnetic quantities (6)
- Magnetic field intensity
- Magnetic flux
- Magnetic flux density
- Magnetomotive force
- Permeability
- Reluctance
What is scientific notation
Quantities as a product of a number between 1-10 and a power of 10
(150,000 = 1.5 x10^5) (0.00022 = 2.2 x 10^-4 )
What is engineering notation ?
A number can have from 1-3 digits to the left of the decimal point and the power of 10 must be a multiple of 3
(82,000 = 82 x 10^3), (243,000 = 243 x 10^3) , (1,956,000 = 1.956 x 10^3 )
(0.0022 = 2.2 x 10^-3), (0.000000047 = 47 x 10^-9)
Pico (p) is what value ?
10^-12 or Trillionth
Nano (n) is what value?
10^-9 or Billionth
Micro ( u) is what value
10^-6 or Millionth
Milli (m) is what value?
10^-3 or Thousandth
Kilo (k) is what value ?
10^3 or thousand
Mega (M) is what value ?
10^6 or million
Giga (G) is what value ?
10^9 or Billion
Tera (T) is what value ?
10^12 or Trillion
What are the 3 rules for metric unit conversions ?
- Determine how far to move the decimal by determining the difference of the powers of 10
- If it’s larger to smaller move decimal to the RIGHT
- If it’s smaller to larger move decimal to the LEFT
All matter is made of atoms, all atoms have…(3)
Protons, neutrons, and electrons (planetary structure)
How are elements arranged in the periodic table ?
The atomic number ; number of protons in the nucleus
Electrons orbit the nucleus at certain _________ electrons further from the nucleus are at higher energy levels. Electrons at the highest energy levels exist in the _______ _____ . These electrons are called _______ _________.
- Distances
- Valence Shell
- Valence Electrons
When high energy electrons escape the atom becoming a ____ electron. Once this happens it can be influenced by an ________ or ________ field.
- Free
- Electric
- Magnetic
Why is copper the most commonly used metal in electric applications ?
29 electrons orbit the nucleus in 4 shells
What are conductors ? (+1what is the best conductor)
Material that allow current usually due to a high number of valence electrons.
SILVER
What are semi conductors ? (+2 common materials ?)
Material with fewer valence electrons about only 4. They carry current worse than conductors.
Silicon and Germanium
What are Insulators ? ( +1 for naming a material )
Material that are poor conductors of electric current . No free electrons . Mostly used to prevent current where it is not wanted.
Glass
Electrical charge exists because of an ______ or _________ of electrons
- Excess
- Deficiency
(Static electricity is the presence of a net positive or net negative charge in material)
It is the ________ _____ that exerts force on another charge
Electric Field
Materials with charges of opposite polarity are _________ to each other, and materials with charges of the same polarity are ________
- Attracted
- Repelled
What law describes the force between two point charges, stating that the force is directly proportional to the product of their charges and inversely proportional to the square of the distance between them?
Coulombs Law ; Bigger charges = bigger force , Closer charges = stronger force
Charges are like magnets either pushing or pulling away from one another
The strength of the push or pulling depends on the size of the charges.
The distance matters, the force doesn’t change liberally it changes fast. Force gets 4 times weaker when the distance doubles .
Electrical Charge (Q) is measured in ________ (_)
Coulombs (C)
What is the equation for total charge ?
Q= n x e
N = number of electrons
E= (1.6 x 10^-19C)
What is 1 Volt defined as
One volt is defined as the amount of electric potential difference or electromotive force that will move one coulomb of charge with one joule of energy.
Volt = W (work/ energy) 1 Joule
___________________. ____________
Q (charge). 1 Coulomb
What is electrical current ?
The rate of flow of charge ( number of electrons flowing past a point in a unit of time )
I (in Amps) = Q ( Charge;in coulombs )
_____________________________
t (time; in seconds)
When there is current in a conductor, ____ _________ collide with atoms. Sometimes causing a ____of some energy. This restriction is called __________
- Free electron
- Loss
- Resistance
What is the opposite of resistance ? (+1 what is the equation and SI unit )
Conductance (G) - measures the ease of which current is established
G = 1/R
Siemens
In a 4 band resistor code what are the rules to reading them (4)
1st digit = first number of resistance value
2nd digit = second number of resistance value
3rd digit= number of zeros ( multiplier )
4th digit = percent tolerance
What is the 4 band resistor code ?
0-black +/- 5% = gold
1-brown +/- 10% = silver
2-red
3-orange
4-yellow
5-green
6-blue
7-violet
8-gray
9-white
In a 5 band resistor code what are the rules to reading them (4+ 5+)
1st band = first number
2nd band = second number
3rd band = third number
4th band = number of 0’s (multiplayer) ( 0.1= gold and .001 =silver)
5th band = tolerance ( +/- 2% = red
+/- 1% = brown
+/- .5% = green
+/- .25% = blue
+/- 0.1 % = violet )
What are the 5 band color codes
0-black
1-brown
2-red
3-orange
4-yellow
5-green
6-blue
7-violet
8-gray
9-white
What are all three forms of Ohm’s Law ?
- I=V/R
- V=IR
- R=V/I
(2 divide and 1 multiply )
Energy is the ability to do ____ and power is the ____ at which ______ is ____
- Work
- Rate
- Energy
- Used
What are the 3 equations for power ?
- P=I^2 R
- P=VI
- P=V^2/R
What tells you the amount of heat a resistor can give off before damage ?
Power rating
When electrons give off heat as it moves through material / resistors is called ?
Voltage drop
Devices that convert energy from one form to another (usually AC to DC ) are called ?
Power supplies
What is the equation for voltage drop ?
I x R
When adding the algebraic sum of multiply voltages, the ________ of all the sources must be included ( ) or ()
Polarity
(-)
(+)
The direction of voltage can also be referred to as
Polarity
The law that states the sum of voltage drops equals total source voltage is
Kirchhoffs Law
Voltage _____ always have ________ __________ to the source voltage polarity.
Drops
Opposite
Polarities
An adjustable resistor with 3 terminals
Potentiometer
