Chapter 13-Electricity & Electric Circuits
Electric impedance (_) includes: ____ (_) and ____(_)
(Z); Resistance (R); Reactance (X)
All circuits can be divided into __ circuits and __ circuits.
AC; DC...
Thermal noise is controlled by _______. Transmitted noise is controlled by _________. Interference noise is controlled by __, ___, and ____.
Appropriate construction of transmission circuitry (wire selection); Noise reduction techniques during signal generation and transmission; Grounding, balancing, and electromagnetic shielding
When sound is converted into its electrical form, it is called an _____.
Audio signal
___ (_) is the ability of matter to store electric charge and sustain the existing voltage by opposing the flow of direct current.
Capacitance (C)
Reactance (X) depends on: ____ reactance (___) and ____ reactance (_)
Capacitive (Xc) Inductive reactance (XL)
Matter that has low electric impedance and conducts electricity easily is called a ____. Matter that has high electric impedance and allows very few electrons to flow through is called an ___ or ____.
Conductor; Insulator; Dielectric
An inductor does not oppose ____. An inductor opposes ____, and this opposition increases as the ____ increases. *Inductance/inductors oppose _____.
DC current; AC current; frequency of the AC increases; high frequency
A battery is an example of a___. A standard wall outlet is a source of ___ (standard frequency for America is ___Hz)
DC; AC; 60Hz
The source of electricity can cause the current to flow in one direction:_____ (_), or can cause the current to reverse polarity periodically: ____ (_).
Direct current (DC) Alternating current (AC)
The ___ ground connects the metal enclosure of a device to a conductor buried in the ground. During an equipment failure, the voltage will be transferred to the ___ instead of the person.
Earth; earth
Sound is measured, recorded, transmitted, and manipulated in its ____ form, not its acoustic or mechanical form.
Electric
For an electric current to flow, it needs an ___, that is, a pathway that allows the flow of an electric current from one pole of an energy source to another.
Electric circuit
Randomly drifting electrons can be organized and start flowing in one direction. This flow of free electrons is called _____ (_)... and is measured in ____. (_)
Electric current (I) Coulombs (C)
_____ is a form of energy resulting from an uneven distribution and directional flow of electrons.
Electricity
The force that moves the free electrons is called an ______ (___ or __). This force is need to pass an ____ between two points in space.
Electromotive force (EMF or E) Electric charge
The amount of energy stored in electric and magnetic fields that can be released under some conditions is called ___.
Flux
Both electric and magnetic fields are characterized by their respective ___ and _____.
Flux Flux density
Thermal Noise-___________ Transmitted noise-_________ Interference Noise-________
Generated by the elements transmitting the signal; Delivered to the circuit as a part of the original signal; Created by surrounding electromagnetic fields (radio stations)
Types of Force Fields: Gravitational Field- ____ Electric Field-____ Magnetic Field-_____
Gravitational- one mass attracts another mass Electric- charged particles can attract or repel each other Magnetic- changes in current flowing in one circuit change the current flowing in another circuit or the electric current moves objects that are passing the current
When atoms of boron are added to the silicon, there is a deficit of electrons ("___" in the ____). A semiconductor with a deficit of electrons is called a ____. The impurities increase the ____ of the silicon.
Holes; valence shells P-type; electrical conductivity
_____(_) is the ability of matter to store energy in a magnetic field and resist change in CURRENT (unlike capacitance, which resists changes in ____).
Inductance (L); capacitance
The most dominant noise, the one that is most difficult to suppress, is ____.
Interference noise
In an AC circuit, the flows of electrons is in ____ for half of each cycle and in the ____ for half of each cycle.
One direction; other direction
If an external force is applied, randomly drifting electrons can be _____________.
Organized and flow in one direction
If a DC voltage is applied to the PN junction, the current will flow THROUGH the junction IF: the positive terminal of the battery is connected to the ___ and the negative terminal is connected to the ___. This is callled ___-biased.
P type; N type; Forward-biased
When P-type and N-type materials are connected together, they create a ______. Where the P-type and N-type materials connect, some of the electrons from the N type ____ in the P type, creating a ____.
PN junction; fill in the holes depletion zone
____, in a circuit, alter the current and voltage at various points WITHOUT requiring additional energy. Include: __,___, &____
Passive elements resistors, capacitors, and inductors
Uneven distribution of electrons=____ Directional flow of electrons=___
Potential energy Kinetic energy
Resistance can be varied in a resistor called a ____.
Potentiometers (trimpots, volume controls)
An AC source provides the SAME power as a DC source when the ____________.
RMS magnitude of the AC source is equal to the amplitude of the DC source
___ affects the current flow in both AC and DC, whereas ___ and ___ affect the current flow only in AC circuits, since their opposition to current flow is a function of ____.
Resistance capacitance and inductance frequency
___(_) opposes the flow of electric current through matter and converts the passing current into HEAT. The unit is the ___. (_)
Resistance (R) Ohm (Ω)
The electric power in an AC system is equal to the ____ (___) magnitude, not the ____.
Root mean square (RMS) Amplitude
Matter than can conduct electricity under some conditions but not under others is called a ____. These are good materials for controlling the _____ and are used in various electronic devices. (such as amplifiers and switches)
Semiconductor; flow of electric current
Semiconductors are commonly made out of ___ with impurities, such as ___ or ____, added. ___ atoms bond together in pairs to form a very stable molecule called _____.
Silicon; boron; phosphorus; Silicon; Crystalline silicon
Ohm's Law:
The intensity of an electric current is directly proportional to the voltage and inversely proportional to the resistance of the current flow. (I=E/R)
Electric noise consists of three main elements:
Thermal noise; Transmitted noise; Interference noise
____ are two semiconductor junctions connected together in a PNP or NPN sandwich. Amplify signals in ____ systems and switch signals ___ and ___ in ____ systems.
Transistors; analog; on and off; digital
Newton's Law of Gravitation:
Two bodies (masses) separated in space attract each other with a force (G) called the force of gravitation (gravitational field)...
EMF is also called ___ and _____. And is measured in ___.
Voltage Potential difference Volts
_____ also alter current and voltage, but they require additional sources of energy. EX: vacuum tube
active elements
All matter is composed of ___. (made up of ___ (_), ___(_), and ___.
atoms protons (+) electrons (-) neutrons
____ provides a device with protection against low-frequency and high-frequency electromagnetic fields.
balancing
Three parts of a transistor (terminals):
base, emitter, collector
If an electron on the valence shell is attracted by another atom, it can __________, becoming a ____.
break away and drift becoming a free electron
The amount of opposition to AC current is called _____ (_) and it depends on: 1-_______ 2-_______
capacitive reactance (Xc) the capacitance of the capacitor; frequency of the applied AC voltage
A ____ is an electric element that is capable of storing electrostatic charge. Consists of two ____ (____) separated by a narrow layer of a dielectric (insulting) material such as ___,___,___, or ___.
capacitor; parallel metal plates (sheets); air, paper, ceramic, or plastic
In a DC circuit, a charged capacitor is discharged using a switch to ______________. An example of this is the flash on a camera: operates when the plates of the charged capacitor are ____.
connect the two plates; connected
Electric current is measured in the number of ____ passing through a point of observation in 1 second. The current resulting from 1 coulomb of electricity passing through a point of obervation in 1 second is called 1 ___ (_).
coulombs ampere (A)
Electric installations need to be protected from: ___ (signal leaks) ___(various noise sources)
crosstalk; electric noise
Impedance refers to the opposition to ________________
current produced by AC circuits
A ____ is an electronic device that passes electric current only in ONE direction. Can be used to change ___ voltage into ___ voltage.
diode; AC; DC
The main form of semiconductor components are ___, ___, and ___.
diodes; transistors; integrated circuits
By changing the ____ and amount of ____ polarizing the PN junction, the amount of ____ (______) passing through the junction can be controlled.
direction; voltage; current (flow of electrons)
Electric flux is the amount of ___ acting over a specific surface. The ability of an electric field to transmit flux is called the ____( ) of the field.
electric charge; permittivity (ε)
The source of electricity and various electric components connected together are called ____, such as a ____. (created by wires connecting a series of various elements)
electric circuit loop
Electric charges produce an ____ and causes the flow of current. The flow of a current produces the ____. This interaction results in an _____.
electric field magnetic field electromagnetic field
An ____ results from the PRESENCE of opposing stationary charges. A ____ results from the MOVEMENT of charges.
electric force magnetic force
The opposition of matter (resistance, capacitance, and inductance) to electric changes is called the ____(_).
electric impedance (Z)
The component that uses electricity for a specific work is called the ___. This can be ___ circuit or an ___ circuit.
electric load closed (with a load) open (without a load)
The chassis ground connects all the ______ within a device together in one place to avoid ______ created within the device.
electric pathways; spurious signals
An ____ is a device used for disconnecting (____) and connecting (____) the pathway of an electric current. Described in terms of ___ (the number of pathways) and ____ (how many positions)
electric switch; open; close; pole; throw
A magnet can be created by passing a current through a coil of wire wound around a metal core. This electric source of a magnetic field is called an _____, and is a ____ magnetic force.
electromagnet temporary
The intensity of electric current (I) is determined by the number of ___ passing through a point of observation in 1 second. In other words, the intensity of electric current is defined as the amount of electricity, called the _____ (_).
electrons electric charge (Q)
The ___ of an atom orbit the nucleus in ___ shells. The farther away the shell is from the nucleus, the ___the force of attraction.
electrons electron weaker
Remember: resistance opposes the ________.
flow of energy
A ____ is an area in which a force such as gravity, electricity, or magnetism causes an object to be affected a certain way.
force field
If the transformer ratio is properly selected, the transformer can match the _______ to the ______.
impedance of the load; impedance of the signal source
The opposition to the flow of AC through an inductor is called _____.
inductive reactance
An ____ is an electric component (a coil of ____ wrapped around an ____) that has a high _______ and prevents changes in the magnetic field produced by a ____.
inductor; wire; insulting core; inductance; passing current
An ____ (_ or ___) is a complete circuit that is etched into a semiconductor.
integrated circuit; (IC, or chip)
The optimal transfer of power that occurs when the impedances are matched is desirable for providing power to ___ and ____ and for feeding an _____________.
light bulbs; electric tools; audio signal into a loudspeaker
Capacitance and capacitors oppose ______.
low frequency
When an electric current flows through the wire coil of an inductor, it generates a ______, which in turn generates its own current that ___________.
magnetic field; opposes changes to the primary current
Magnetic flux is the amount of ____ acting over a specific surface. The ability of a magnetic field to transmit flux is called the ___ (_) of the field.
magnetism permeability (µ)
When various electric devices and systems work together, they form structures called ____. They can be wired or ___. The cables and elements that connect a system via wires are called an ______.
networks; wireless; electric installation
Grounding means connecting all electric circuits to _____ (the ___) that has a very _______. Includes: ___ (safety, power) and ____ (signal, common)
one common point; ground; low resistance; Earth; Chassis
During the first part of an AC circuit cycle (of a capacitor), electrons are stored up on ____ of the capacitor (_), and the _____ becomes more ___(_). During the second part, the stored electrons (_) flow back through the circuit and the electrons are then stored ___________.
one plate; (-); other plate; positive (+); (-) on the opposite side of the capacitor
The parallel plates of a capacitor separate ____ (_ & _). The ___ attract each other, which create an ______.
opposite charges (+ and -) charges; electric field
When the electrons in a material are lined up along the same axis, they create a _____, formed by materials called _____.
permanent magnet ferromagnetics
When atoms of ___ are added to the silicon, some atoms from the ___ are free to drift around the material. A semiconductor with a surplus of electrons is called ____.
phosphorus; phosphorus; N-type
EMF is caused by the collection of ______ at one location (___) and ____ at another location (___). Electric current flows is there is a pathway between the ____.
positively charged ions (positive pole) negatively charged ions (negative pole) two poles
The change from stored electric energy to a flow of current is a change from ____ to ____. When current flows, it causes a decrease in the EMF, called a _____.
potential energy kinetic energy voltage drop
In electric systems, a source of energy provides a constant supply of _____ and the source and the load are _________. Optimal power transfer occurs when the impedances of the source and the load are ____.
power; physically connected; matched (equal)
An electromagnetic field is the interaction between the ____ and the _____. Alternating ___ and ___ fields always interact and they create each other.
presence of particles possessing an electric charge; magnetic field generated by the relative movement of these particles in space; electric and magnetic
A ___ is an element of an electric circuit that has a known resistance and provides a specific opposition to a current passing through the circuit. The amount varies based on the ___ ,___, and the ____.
resistor; shape& size (volume) and material from which it is made (commonly carbon)
DC electric circuits include: ____ AC electric circuits include: _________
resistors; resistors, capacitors, and inductors
If a battery is connected in reverse (___-____), then current _____ flow through the junction.
reverse-biased; will not
A ____ is a material that conducts electricity under some conditions but not others. Useful for building ___ and ___ that control the flow of electric current.
semiconductor; switches and amplifiers
The components of a circuit can be connected in one continuous loop called a _____. Alternately, the components can form several branches connecting the same two points in a ______ (because the signal is split up).
series circuit; parallel circuit
Induction coils are used as ____, since they oppose rapid (_______) changes in voltage.
surge protectors; high frequency
Balancing (____) lines involve two signal conductors carrying _______________. At the output the signals are ____ from one another, causing the output signal to be twice as large and eliminating ____ noise that was induced in both lines. A pair of wires in a ____ should run tightly together and should be twisted for optimal balancing.
symmetric; the same signal in opposite phase; subtracted; in-phase; symmetric line
Electromagnetic waves travel at ____.
the speed of light
The ____ (_) is the ratio of the number of turns in the primary coil (__) to the number of turns in the secondary coil (_): r= __/___
transformer ratio; (r); (Np); (Ns); r=Ns/Np
An electric ___ is a device that matches the electric impedances of two ____ circuits. It consists of a primary ____ connected to the source of the signal and a secondary _____ connected to the load.
transformer; AC; wire coil; wire coil;
Electric and magnetic fields can be thought of as families of invisible lines of force connecting the _____ (_&_) and organizing ____ along these lines.
two opposing poles (N & S) particles of matter
Impedance "mismatching" is an ___ or ____
underload or overload
Electromagnetic shielding (EMS) reduces the amount of _____ (in the pathways of an electric device) caused by _________ and also prevents signals within devices from _____. Does not offer much ___ against static and ______ magnetic fields. (60Hz)
unwanted currents; external (interfering) electromagnetic fields; leaking out; protection; low frequency
The outer shell of an atom is called the ____.
valence shell
Electric power (P) is the product of ___ (_)and ____(_). The formula: P=_x_. The unit of electric power is the ___ (_).
voltage (E); electric current (I); watt (W)...
Kirchhoff's Laws (2) describe the relationship between ____ and ____ in serial and parallel electric circuits: 1. ________ 2.__________
voltages; currents; The sum of all electromotive forces and voltage drops in any circuit loop must equal 0; The sum of all the currents arriving at and leaving from any juncture point in a circuit must equal 0