EE Flashcards
A property ascribed to phenomena, bodies or substances that can be quantified for, or assigned to a particular phenomenon, body, or substance.
Quantity
A quantity that can be used in the mathematical equations of science and technology
Physical Quantity
A particular physical quantity defined and adopted by convention, with which other particular quantities of the same kind are compared to express their value
Unit
The smallest portion into which an element can be subdivided without losing its physical and chemical properties
Atom
If an object contains more number of total electrons than the total protons
Negatively charged
If an atom contains of fewer number of electrons than the number of electrons
Positively charged
Amount of electrical charge on a single electron
Elementary Charge Unit (ECU)
Used to measure quantity of electric charge; approximately equal to 6.24 x 10^18 ECU
Coulomb (C)
The result of non-random movement of electrons
Current
Defined as the rate of electrical charge flow
Current (I)
Causes electric charge to flow in an electrical system having potential difference
Electromotive force and potential difference
The ability of a material to resist the flow of electrical charge when subjected to a given potential difference
Electrical Resistance
Property of materials to oppose the flow of electric current
Resistivity
Material which has low resistance to electron flow
Conductors
Material which has high resistance to electron flow
Insulators
Materials having an intermediate resistance to electron flow; usually used in construction of solid state electronic devices such as diodes and transistors.
Semi conductors
reciprocal of resistance, measured in mhos
conductance
ability of materials to conduct electricity
conductivity
a phenomenon when conductors lose their resistance in extreme cold
superconductivity
components are connected end-to-end in a line to form a single path for electrons to flow
series connection
all components share the same (equal) current
series connection
all components are connected between the same set of electrically common points
parallel connection
all components share the same (equal) voltage
parallel connection
measured in farad (F)
capacitance
the concept is closely related resistors connected in series
Voltage divider
the voltage across each resistors is _________ to the ratio of its resistance to the total series resistance of the circuit
directly proportional
the concept is closely related to resistors in parallel
current divider
the current divides in ______ to the resistances of the individual parallel elements
inverse proportion
it is always possible to view a very complicated circuit in terms of much simpler equivalent source and load circuits
Equivalent Circuits
from the point of view of the load, any network composed of ideal voltage and current sources, and of linear resistors, maybe presented by an equivalent circuit consisting of an ideal voltage source in series with an equivalent resistance
Thevenin’s Theorem
from the point of view of the load, any network composed of ideal voltage and current sources, and of linear resistors, maybe presented by an equivalent circuit consisting of an ideal current source in parallel with an equivalent resistance
Norton’s Theorem
States that the current flowing in a circuit varies directly with electrical pressure and inversely with opposition
Ohm’s Law
in kirchoff’s voltage law, the sum of the voltage around a closed path is equal to _______
zero
in a closed path, the sum of the voltage rise is equal to the voltage drop
kirchoff’s voltage law
because charge cannot be created but must be conserved, the sum of the currents entering a node is equal to the sum of the currents leaving the node
kirchoff’s current law
an instrument that gives a reading of the product of the current and the voltage in a circuit
wattmeter
the value of the power factor depends on the kin of opposition offered. It is never ______ than 1
greater
for heaters, incandescent lamps and electric ranges, power factor is ____ to 1
equal
for electric motors, power factor ranges between _____
0.6 to 0.8
it is power expended or used over a period of time
energy
common unit of electric power is_____
watt
common unit of electric energy consumption is ____
watt-hour
this type of meter is used for billing customers for electric usage
kilowatt-hour meter
characterized by non-variant current flow in one direction at all times
direct current (DC)
characterized by an alternating flow of current in two directions
alternating current (AC)
a plat of values of quantities which vary with time
waveform
signal that repeats the same shape at regular intervals of time
periodic waveform
the magnitude of a waveform at any instant of time
instantaneous value
the maximum instantaneous value of a function from zero-volt level
Peak Value
the sum of the magnitudes of the positive and negative peaks
peak-to-peak value
the time interval between successive repetitions of a periodic waveform
period