Electricity and Magnetism FULL Flashcards
What two types of electric charge are there?
Positive and negative
Which particle carries negative charge?
Electrons
Which particle carries positive charge?
Protons
Which particle has no charge?
Neutrons
What happens when similar charges are near each other?
They repel
What happens when opposite charges are near each other?
The attract
How would a neutral object become charged?
By rubbing two insulating materials together
Which particle always moves when objects are rubbed together?
Electrons
Which force is required to move electrons?
Friction
What type of materials are needed for static charge to build up?
Insulating materials
How does lightning occur?
Electrons jump from the cloud to the ground creating a large current. This is seen as lightning.
What is an electric field?
An area where an electric force acts on a charged object
Define current
The amount of charge flowing per second
What does a closed switch do?
It completes the circuit and allows current to flow
What does an open switch do?
It opens the circuit and does not allow current to flow
What instrument measures current?
An ammeter
What is the symbol for an ammeter?
A (in a circle)
What are the units of current?
A (Amps)
Do ammeters need to be connected in series or parallel for them to work?
Series
Define potential difference
How much energy each charge as (it gives the electrons a push)
What instrument measure potential difference?
Voltmeter
Do you connect a voltmeter in series or parallel?
Parallel
What are the units for potential difference?
V (Volts)
What is another term for the value of potential difference?
Rating
What is a series circuit?
A circuit with one loop
What is a parallel circuit?
A circuit with more than one loop
What is an advantage of a parallel circuit?
If one component breaks, the others will still work
In a series circuit the current is always
The same everywhere
In a parallel circuit the current
Is split (I1 = I2 + I3)
Is a series circuit the potential difference
Is shared (V1 = V2 + V3)
In a parallel circuit the potential difference
Is the same across each junction
What is resistance?
How difficult it is for current to flow through a material
What is the unit of resistance?
Ohm
What device can measure resistance?
Ohmmeter
A material with a very high resistance is called an
Insulator
A material with a very low resistance is called a
Conductor
What is the equation to calculate resistance?
R = V / I
What are the three magnetic materials
Iron, Nickel and Cobalt
What are the two poles of a magnet
North and South
What happens when similar poles are near each other
They repel
What happens when opposite poles are near each other
They attract
Which way do magnetic field lines go
From north to south
What is created when a current flows through a wire
A magnetic field
How can we increase the magnetic field produced by a wire
Coil the wire or put more current through it
What do we call the magnet created by electricity?
Electromagnet
How else can we increase the strength of an electromagnet
Wrap the wire around an iron core
A motor uses an electromagnet to turn, it also needs what other component
A permanent magnet
How can you make an electric motor spin faster?
Increase the current, increase the number of coils
How can you make an electric motor reverse it’s direction?
Change the direction of current, swap the permanent magnet around
What does repeatable mean?
When you repeat an experiment AND get similar results
What does reproducible mean?
When someone else repeats an experiment AND gets similar results
