Electricity and Electronics Book
A wattmeter measures the
instantaneous power used in a circuit, and a watt-hour meter measures the amount of power used in a circuit over a period of time.
Four factors that affect the resistance of a conductor are
length, cross-sectional area, temperature, and type of material.
Photoresistive cells are
light sensitive resistors.
A photovoltaic cell produces electricity from
light.
Conductors provide a __________ path while insulators provide a __________ path.
low resistance (conductors), high resistance (insulators).
Batteries are
two or more cells connected together.
Some popular primary cells include the
zinc-carbon cell, the alkaline cell, the mercury cell, the lithium cell, and the silver oxide cell.
Voltmeters measure
voltage and are connected in parallel with the component to be read. Multiplier resistors are connected in series with voltmeters to increase the range of the meter.
Connecting cells in series (- to +) increases their ________, while connecting them in parallel (- to - and + to +) increases their
voltage rating, current rating
A mil equals
1/1000 of an inch.
One horsepower is equal to
746 watts.
Chapter 3
Introduction to basic Electrical Circuit Materials
There are definite relationships between
Ohm's law and Watt's law.
Chapter 7
Parallel Circuits
_________ cannot be recharged, while ___________ can be recharged.
Primary cells, secondary cells
There are a number of different types of electrical diagrams. They include:
Schematics, wiring diagrams, line diagrams, and block diagrams.
Chapter 1
Science of Electricity and Electronics
Chapter 6
Series Circuits
Chapter 5
Sources of Energy
Induction occurs when
a charged body is brought close to another body.
A multimeter is one instrument that will measure
a number of different types of values, such as current, voltage, and resistance.
The coulomb is
a quantity of electrons (6.24 x 10^18)
When a voltmeter is connected across a circuit to measure a potential difference, it is
in parallel with the load in the circuit. This situation can introduce errors in voltage measurement.
Total power consumed in the series circuit is equal to the
sum of the individual power consummation (PT = Pl + P2 + P3... + PN).
Total power consumed in the circuit is equal to the
sum of the individual power consumptions (PT = Pl + P2 + P3... + PN).
The source voltage is equal to the
sum of the voltage drops in a series circuit (ET = El + E2 + E3... + EN).
Cells are
the basic unit for producing electricity by chemical action.
The negatively charged particle of the atom is
the electron and the positively charged particle is the proton.
Switches are used to control
the flow of electrons through a circuit.
The basic meter movement used for many analog instruments is.
the moving-coil galvanometer, or the D'Arsonval movement
Efficiency is equal to
the power out divided by the power in.
Watt's law is a mathematical formula stating
the relationship of the power, voltage, and current in a circuit. It is P = I x E.
The amount of work done can be manipulated by gears and pulley systems while maintaining
the same horsepower.
Molecules are
the simplest form of a compound still having the unique characteristics of that compound.
Atoms are
the simplest forms of an element still having the unique characteristics of that element.
Power is
the time rate of doing work.
The device used to produce electricity by heat is the
thermocouple.
There are two types of current
, AC (alternating current) and DC (Direct Current).
Chapter 2
Basic Instruments and Measurements
Chapter 8
Combination Circuits
Ohm's law can be stated three ways:
E = IR, I = E/R and R = E/I
Chapter 4
Energy
Switches are classified according to their
actuator, internal electrical circuitry (poles and throws), ampacity, and voltage.
The sensitivity of a meter is
an indication of its quality. Sensitivity is measured in an ohms-per-volt rating. Another system of rating accuracy is based on percentage of full scale reading.
A meter used to measure the value of an unknown resistance is called
an ohmmeter. Ohmmeters are connected across the resistance being measured.
It is vital to observe correct polarity in the use of
analog meters.
Matter is
anything that occupies space or has mass.
Conductor insulation varies according to
application.
Unlike charges
attract each other.
Elements are
basic or pure forms of matter.
Troubleshooting a combination circuit uses the techniques developed for troubleshooting
both series and parallel circuits.
Electricity can be produced by
chemical action.
Ammeters measure current and are
connected in series in a circuit. Shunts are resistors connected in parallel with ammeters to increase the range of the meter.
Correct polarity must be observed when
connecting electrical devices.
Battery capacity is a
current producing rating measured in ampere-hours (Ah).
A circular mil equals the
diameter (expressed in mils) squared, or D^2, for a round conductor.
Digital meters give values in
discrete amounts in units 0-9.
In a parallel circuit, the voltage is
equal through the circuit ((ET = El = E2 = E3... = EN).
In a series circuit current is
equal throughout the circuit (IT = Il = I2 = I3... = IN).
Kirchhoff's current law states that the total current entering a junction or parallel circuit is
equal to the current leaving that junction or parallel circuit.
Linear meter scales have
evenly spaced marks. Ammeters and voltmeters us linear scales.
Nonlinear scales do not have
evenly spaced marks. Ohmmeters use a nonlinear scale.
Electric lamps may use
filaments or ionized gas as a conductor.
Resisters are manufactured in many different ways, and they come in
fixed and adjustable packages.
Voltage is the
force behind the electrons. It moves them along a conductor resulting in current.
Work is equal to
force times distance.
Color codes are used to
identify resistor resistance values.
Mechanical power is
measured in horsepower.
Electrical power is
measured in watts.
Compounds are
mixtures or combinations of two or more elements.
A parallel circuit provides
more than one path for current flow.
Current is the
movement of electrons in a conductor.
The law of conservation of energy states the energy can
neither be created nor destroyed. It can only be converted from one form to another.
A series circuit provides
only one path for current flow.
Efficiency is expressed as a(n):
percentage and indicates how well one form of energy is converted to another form of energy.
Electricity can also be produced by applying pressure to certain objects such as
quartz, tourmaline, and Rochelle salts.
After total current is found in a combination circuit, the original circuit can be
reconstructed and individual voltages and currents found by applying the characteristics of series and parallel circuits.
Any complex combination circuit can be
reduced to an equivalent resistance or simple circuit.
Like charges
repel each other
Digital meters are
rugged, small in size, accurate, and portable.
Analog meters use a
scale with continuous variable values.
Nickel-cadmium cells and lead-acid cells are
secondary cells.
The total circuit resistance is always less than the
smallest resistance value in the parallel circuit.
After the total resistance of a combination circuit is reduced to a simple series or parallel circuit, the
source voltage can be applied and the total current value determined.
Total power consumed by a combination circuit is equal to the
sum of all individual component power consumption wattages.
The total resistance in a series circuit is equal to the
sum of all the resistance values in the circuit (RT = Rl + R2 + R3... + RN).
The total circuit current value in a parallel circuit is equal to the
sum of the individual current values (IT = Il + I2 + I3... = IN).
