Vocabulary Flashcards
static electricity
a charge produced
by rubbing or touching objects
together
Law of Charges
Laws that describe the behaviour between charged and uncharged objects: 1. Unlike charges attract 2. Like charges repel 3. Charged objects attract uncharged (neutral) objects
Insulators
any material in which the
charge stays on the spot where the
object is rubbed; most non-metals
are insulators
conductors
materials that allow
charges to move freely; most metals
are conductors
Superconductor
materials that offer
little or no resistance to the flow of
charges
discharge
the re balancing of
an unbalanced charge; felt as a shock
or seen as a spark
Circuit
path for transmitting electric current.
Battery
a combination of cells, either
wet or dry
galvanometer
an instrument used to
measure very weak current
ammeter
an instrument used to measure larger currents
ampere
the unit used to measure
electric current (A). Milliamperes
(mA) is also commonly used
potential difference
the difference
in potential energy per unit of charge
between one point in the circuit and
another point in the circuit
voltmeter
the instrument used to
measure voltage
resistance
the property of a substance that hinders motion of electric charge and converts electric energy into other forms of energy
ohmmeter
an instrument to directly measure resistance
current
a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space
series circuit
circuits with only one current path
parallel circuit
circuits with several current paths
Thermocouple
a loop of two wires
made of different types of metals that
converts heat to energy
thermo-electric generator
plants that burn fossil fuels to produce
electricity
piezoelectric effect
sound produced
when an electric current causes
vibrations in a tiny crystal
photovoltaic cell
a device used
to produce electricity
from light
electrochemical
device that can generate electrical energy from the chemical reactions occurring in it, or use the electrical energy supplied to it to facilitate chemical reactions in it
electrode
the two metals in a
voltaic or electrochemical cell
electrolyte
a substance that conducts
an electric current, and in which the
electrodes are placed
primary cell
an electric cell that produces current by an irreversible chemical reaction.
secondary cell
A rechargeable electric cell that converts chemical energy into electrical energy by a reversible chemical reaction
electric generator
a device that
converts mechanical energy into
electric energy
electromagnet
a strong temporary
magnet, created by inserting a soft
iron core into a coil of wire and then
passing a current through the wire
alternating current
electricity
produced in a generator where the
current flowing from the generator
changes direction regularly
direct current
current that
flows in one direction only
dynamo
a generator that produces
direct current
split-ring commutator
two metal half rings connecting either end of the rotor coils to the brushes.
stator
a stationary part of a
motor surrounding the rotor.
The simplest form of stator is a
two-pole electromagnet
transformer
used to “step-up” the
voltage for efficient transmission of
current over long distances
circuit breaker
acts as a switch and safety device that can cut all power coming into the home
fuse
a device containing a metallic
conductor that melts when heated by
excessive current
Neutral wire
one of the “live” wires in electric cables, which returns low energy electricity back to the breaker panel; the neutral wire is white and insulated
hot wire
one of the “live” wires in
electric cables, which carries high
energy electricity; the hot wire is
black and insulated
ground wire
a device to safely channel any energy that has “leaked” out;
the ground wire is either bare copper
or covered with green insulation
transistor
electronic switches in
modern digital devices
power(formula)
energy per unit time.
Power Energy/Time
watt
a unit of power equivalent
to one joule per second; 1 W = 1 J/s
electrical code
the set of standards
for electrical work
electrical efficiency
efficiency = energy out energy in × 100 %.
short circuit
occurs when the wires
in an electric cord accidentally
connect, usually because of frayed
insulation
non-renewable resource
fuels that
are consumed faster than they can be
replaced by nature
hydroelectricity
Hydroelectricity, or hydroelectric power, is electricity produced from hydropower.
co generator system
electricity
generating stations that produce
electricity and also supply
thermal energy
solar energy
radiant energy emitted by the sun.
geothermal energy
thermal energy
contained in the inner
portions of Earth
thermal pollution
occurs when
warm water is returned directly to the
lake or river from where it is taken,
increasing the water temperature
