Science 9 - Chapter 8 Test Flashcards
electric potential energy
electric energy stored in a battery. electrons have stored energy and the ability to do work after they leave the battery.
electrochemical cells
convert chemical energy into electrical energy stored in charges. commonly called cells or batteries.
electrodes
batteries have two terminals called electrodes. usually made up of two different metals (but can be metal and another material) in an electrolyte.
electrolyte
substance that conducts electricity. dry cells = moist paste. wet cells = fluid.
energy
the ability to do work
potential difference
change in potential energy per coulomb of charge
volt
Unit of measurement for voltage
voltage
common name for electric potential difference
amperes
unit for measuring electric current (one coulomb of charge passing a given point per second)
circuit diagrams
drawn to represent electric circuits
current electricity
flow of charged particles in a complete circuit
electric circuit
complete pathway that allows electrons to flow. circuit must contain at least one source of voltage. electric potential energy transformed into other forms of energy
battery
combination of electrochemical cells connected (or a single electrochemical cell.) chemical energy separates the negative and positive charges.
terminals
end points where we make a connection. extra electrons accumulate on one of the battery terminals making it negatively charged. other terminal has lost these electrons and is therefore positively charged.
kinetic energy
energy a moving object has because of its motion.
potential energy
energy stored in a object
voltmeter
device that measures the amount of potential energy difference between two locations of charge separation. when you place the connecting wires of a voltmeter across the + and - terminals of a battery, voltmeter displays battery voltage.
groups of batteries
dry and wet cells
dry cells
batteries in device like flashlights, portable CD players, and watches
wet cells
commonly used in cars, motorcycles, and electric wheelchairs
sources of electric energy
friction, piezoelectric crystals, photo-electrochemical cells, thermocouples, generators
ammeter
device used to measure current
electric load
any device that transforms electrical energy into other forms of energy
four basic types of circuit components
source: source of electrical energy
conductor: the wire through which electric current flows
load: device that transforms electrical energy into other forms of energy
switch: a device that can turn the circuit on or off by closing or opening the circuit
difference between static and current electricity
static: charge remains unmoving on insulator
current: charge flows continually through circuit
electric current
charge flowing in an conductor. defined as amount of charge passing a point in a conductor every second.
ohms
measurement of resistance (Ω)
resistors
electrical components used in circuits to decrease current and convert electrical energy into other forms of energy
resistance
slows down flow of electrons and converts electrical energy into other forms of energy. measured in ohms. (Ω)
ohm’s law
Resistance (R) = V/I
Voltage (V) = I*R
Current (I) = V/R
milli (m)
kilo (k)
mega (m)
micro (µ)
one thousandth (1000 milli "things" in a thing) one thousand (1000 "things" in a kilo "thing") one million (1000000 "things" in a mega "thing") one millionth (1000000 micro "things" in a "thing")
Difference between electron flow and current flow
In electron flow electrons are negative and flow from negative to positive. ‘Conventional’ current flow is from positive to negative. This is because early researchers in electricity thought electricity flowed from positive to negative, which is why they called them that in the first place.
