Physics Flashcards
Charge is measured in…
Coulombs (C)
The charge of an atom is… because…
Neutral. They have an equal number of positive and negative charges that cancel out
An atom becomes an ion when it…
Loses or gains electrons
An ion is…
An atom that has lost or gained electrons
When and atom loses electrons it becomes … charged
Positively
When and atom gains electrons it becomes … charged
Negatively
When charged particles interact they will do 1 of 2 things:
Attract or repel
Opposites charges…
Attract
Like charges…
Repel
A material is classified as an insulator or conductor based on…
How easily electrons move through them
Electrons move through materials by…
Jumping from one atom to the next
The atoms that make up conductors have…
Electrons in wide orbits around the nucleus. Making it easy for electrons to move between atoms
The atoms that make up insulators have…
Electrons in tight orbits around the nucleus. Making it difficult for electrons to move between atoms
For electrons to travel through conductors … energy is required
Less
For electrons to travel through insulators … energy is required
Much more
Metals are very good conductors because…
They contain delocalised electrons which are not bound to an atom so can move freely throughout the metal
A material which is a good insulator is…
Plastic
Water is a good conductor because…
It contains many ions
In water, charge isn’t carried by electrons, it’s carried by…
Ions
Pure water is a good … because …
Insulator. Because it contains no charged particles
If electrons are being removed from an object then…
Positive charge is being transferred
If electrons are being transferred to an object then…
Negative charge is being transferred
When electrons are transferred to an insulator they will…
Stay where they are/not distribute
Electrons transferred to a conductor will…
Immediately spread out across the surface
The shape of a conductor affects how charge…
Distributes itself
In spherical conductors charge will…
Spread evenly across the surface
In pointed conductors charge will…
pack more densely into pointed parts
Friction can cause electrons to… making ….
transfer from one material to another. making one positively charged and the other negatively charged
A material with a high electron affinity has a…
stronger attraction to electrons
A material with a low electron affinity has a…
weaker attraction to electrons
Materials that have a weaker attraction to electrons have a…
low electron affinity
Materials that have a stronger attraction to electrons have a…
high electron affinity
If two materials with different electron affinities rub together…
the electrons will transfer from the low affinity material to the high affinity material
High affinity materials include:
plastic materials such as rubber or nylon
Low affinity materials include:
hair glass and wool
2 conductors coming into contact cause a…
charge transfer
when a charged conductor comes in contact with a neutral conductor…
the electrons spread evenly across the 2 objects
Current is measured in…
Amps, A
Conventional current describes the…
flow of positive charge
electron current describes…
how electrons move
voltage is measured in…
volts, V
resistance is measured in…
ohms, Ω
voltage is the…
force a circuit applies to electrons, to move them
resistance is…
how difficult it is for electric current to flow through a circuit
V=IR is called…
ohm’s law
Electric current is…
the movement of flow of electric charge
Electrical energy is the…
amount of power transfered by electrons in a certain time
Electrical energy is meassured in…
joules, J (or kWh)
Electrical power is measured in…
Watts, W
Electrical power is the…
amount of energy used by a circuit each second
P=IV
power = current x voltage
P=E/t
Power = energy/time
A bulb with more electric power supplied to it…
emits more heat and light energy
A circuit is a…
closed loop of wire that electric current flows through
Every circuit has…
atleast 1 component that supplies energy (battery) and atleast 1 component that uses electrical energy(lamp)
cells supply…
electrical energy to a unit
In a cell the longer line is the…
positive terminal
In a cell the shorter line is the…
negative terminal
Electric current flows out of … and into …
positive and into negative
resistors increase…
the resistance of a circuit
resistors control…
the amount of current flowing through a circuit
light bulbs also increase the…
resistance of a circuit
electric current flowing thorugh a component is measured using an…
ammeter
in a series circuit there is only…
1 path for electric current to flow through
In a series circuit current is…
the same everywhere
If a series circuit is broken…
the whole circuit stops working
In a circuit the total resistance is the…
sum of resistances of all components
In a series circuit, voltage supllied is…
divided amognst the components
The voltage across a component is called the..
voltage drop
Adding more components to a seres cicuit increases …. so less….
total rsistance. less current is drawn from the power source. Meaning each voltage drop will become less
The more bulbs youa dd to a series cicuit…
the dimmer they get
Parallel circuits have…
multiple paths for elctrical current to flow through
In Parallel circuits, the current is…
divided amongst the paths
In Parallel circuits, compnents are placed…
on different branches
In Parallel circuits, voltage…
is the same across each branch
Adding more components to a parallel circuit … total resistance, so more ….
decreases. so more current is drawn from the power source
In a parallel circuit if a component stops workign current can…
continue to flow throuhg other branches
in a parallel circuit bulbs stay…
the same brightness
magnetic forces are measured in…
newtons, N
magnetic forces are a…
non-contact force
magnetic forces are generated by…
bar magnets and moving charges
like poles…
repel
opposite poles…
attract
a magnetics field is…
a region of space where a magnetic force can be felt
the symbol for a magnetic field strength is…
B
magnetic field strneght is measured in…
teslas, T
the closer the lines are…
the stronger the magnetic force
magnetic field lines leave the… and enter the…
north pole. enter the south pole
