chapter 17 review: electricity
thunder
a booming or crashing noise caused by air expanding along the path of a bolt of lightning
series circuit
a circuit in which all parts are connected end to end to provide a single path of current
parallel circuit
a circuit that contains more than one path for current flow
closed circuit
a complete circuit through which electricity flows
switch
a device for making, breaking, or changing the connections in an electrical circuit
battery
a device that converts chemical energy to electrical energy
photocell
a device that converts light energy into electrical energy
thermocouple
a device that converts thermal energy into electrical energy
circuit breaker
a device that interrupts or breaks the flow of electricity in an electrical circuit
voltmeter
a device used to measure voltage, or electrical potential energy difference
current
a flow of electric charge
friction
a force that opposes motion between two surfaces that are in contact
lightning
a light produced by electricity in the air, usually during a storm
conductor
a material in which charges can move freely
insulator
a material in which charges cannot move freely
good ground
a material that conducts electricity well to the ground
resistance
a material's opposition to the flow of electric current
electrode
a metal strip that conducts electricity
energy source
a place where energy comes from, such as batteries, food, fuels, and the sun
explain how a lighting rod works
a pointed rod connected to the ground by a wire that absorbs electrical discharge and directs it towards the ground, this helps buildings avoid being electrocuted
wet cell
a primary electric cell in which the electrolyte is a liquid
fuse
a safety device with a thin metal strip that will melt if too much current passes through a circuit
wire
a thin, flexible thread of metal
give examples of insulators and conductors, how is it good ground?
a wire conductor and a basketball as an insualtor
what is not a good ground?
air
dry cell
an electric cell in which the electrolyte is absorbed in a solid to form a paste to prevent spillage
direct current
an electric current flowing in one direction
alternating current
an electric current that changes direction at regular intervals
open circuit
an incomplete electrical circuit in which no current flows
electroscope
an instrument used to detect electric charge
load
anything in a circuit that uses electricity
what is a switch that automatically opens if it's too hot?
circuit breaker
circuit
closed circular line around an area; circumference; regularly repeated journey from place to place
what are the three types of lighting?
cloud to cloud, clouds to ground, ground to cloud
what are the three ways that something can become charged?
conduction, friction, and induction
what is the calculation of electrical energy?
e= pt ( power times time)
the force between two charges is called
electric force
3 types of circuit
energy, wires, loads
explain lighting and thunder an what happens specifically
lighting causes thunder by the air expanding quickly, lighting is electrical discharge and light travels faster then sound, therefore you see lighting before you hear thunder
what are the parts of a circuit?
load, wire energy source
explain resistance and give examples of ways resistance can be changed
material, thickness, length, and temperature is what it depends on
electrons
negatively charged particles
what is the calculation of power?
p= vi ( voltage times current)
protons
positive charge
why is it important that electrons and protons are attracted to each other?
so that they don't break apart
static electricity
the accumulation of excess electric charge on an object
what does the size of electric force depend on?
the amount of charge and distance between charges
what does the size of electric force depend on?
the amount of charge in each object, and the distance between the objects
how do circuit breakers and fuses work
the both protect you from fires, when light bulb gets to hit the fuse breaks
electric current
the continuous flow of electric charges through a material
potential difference
the difference in electrical charge between two points in a circuit, expressed in volts
voltage
the difference in electrical potential energy between two places in a circuit
conduction
the direct transfer of heat from one substance to another substance that it is touching.
watts
unit for power
wattage
unit of electric power
ohms
used to measure resistance to an electrical current
what is the calculation of voltage?
v= ir (current times resistance)
as this increases, so does the current
voltage
repulsion
when two magnetic objects have like poles facing each other, the magnetic force pushed them apart
attraction
when two opposite sides of a magnet go towards each other
what type of charge happens when you rub a balloon on your hair?
friction
cell
in electricity, a device that produces an electric current by converting chemical or radiant energy into electrical energy
law of electric charges
the law that states that like charges repel and opposite charges attract
power
the rate at which work is done
electric discharge
the release of electricity stored in a source
induction
the transfer of charge without contact between materials
amperes
the unit for measuring electrical current, amp