an electric current that reverses its direction at repeated intervals. AC is the abbreviation
direct current
an electric current that flows in one direction only. DC is the abbreviation
dry cell
an energy source that uses dry chemicals. A 9 volt battery is an example
wet cell
an energy source that uses liquid or wet chemicals. A car battery is an example
volt
the measurement unit of voltage. Voltage is reduced by each resistor
voltage
the amount of potential energy that each unit of electrical charge has
V
symbol for volts
amperes
unit for measuring electrical current
amps
abbreviation for amperes and sometimes used for the symobl for amperes
A
symbol for amperes. Amps is a more current symbol
ohms
measure for electrical resistance
abbreviation for Ohms
schematic
a diagram using electrical symbols showing an electric circuit
electrolyte
chemicals that form ions and conduct current when dissolved in water
galvanometer/potentionmeter
a circular device that varies the resistance to electrical current. A dimmer is an example
electrode
a conductor through which electric current is passed. It may be constructed of metal, such as copper, silver, lead, or sinc or nonmetal substance such as carbon
insulator
a material or device that prevents or reduces the passage of electricity heat or cold or sound
resistor
devices that are used to control current in many circuits
series circuit
circuit in which the current has one path
parallel circuit
a circuit in which the current takes more than one path
open circuit
circuit in which there is a break so that current cannot flow
closed circuit
circuit in which there are no breaks and current can flow
fuse
the protection device. Main part is a metal wire or strip that melts when too much current flows which breaks the cicruit
circuit breaker
a device that trips like a switch and opens the circuit when overloaded to prevent fires
coulomb
the unit for electric charge. Its symbol is C
electroscope
an instrument that demonstrates positive and negative charges
load
something that uses electricity
energy source
useful energy can be extracted or recovered either directly or by means of a conversion or transformation process
conductor
something that transfers electricity, heat or cold
semi-conductor
a solid material that has electricity conductivity between those of a conductor and an insulator
Law of Electrical Charges
opposite electrical charges attrace; like electrical charges repel
electric field
the space surrounding an electric charge
electric force
the force that charged objects exert on each other
thermocouple
a device for measuring temperature made of a pair of different metals joined at both ends
photocell
a type of resistor. When light strikes the cell, it allows current to flow freely. When dark, its resistance increases
solar panel
a group of olar cells arranged into a panel that can be installed into flat surface. The panel captures sunlight and convert it into DC power
GFCI
breaks the circuit and is used as a safety device where water is used