electicity and magnetism review
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Review for science test.TRANSCRIPT
Electricity and Magnetism Review
Test Monday
The Nature of Magnetism
Magnetism
Magnetism is the attraction of a magnet for another object.
Poles
Magnets are strongest at the poles
The north pole repels the other north poles but attracts the south poles.
Magnetic Fields
The area of Force around a magnet is know as magnetic Fields.
Magnets
Opposites attract while similar poles repel.
Magnetic Domains
In a magnetic material most of the clusters of billions of atoms, or magnetic domains, have magnetic fields that are lined up in the same way.
Magnetic Domains- clusters of billions of atoms that have a magnetic field that are lined up parallel in the same way.
Magnets being ruined or dropped
If you heat or drop a magnet they can be ruined.
When a permanent magnet is dropped and cracks into a half it creates 2 new magnets.
The Earth as a Magnet
The Earth and Compasses
The earth acts like a giant magnet with 2 poles and a giant magnetic field.
A compass is a device that has a freely spinning magnetized needle.
Magnetic Declination
Magnetic Declination is the angle between geographic and magnetic poles from where you are on the earth.
Current Electricity and Circuits
Current
Current is the flow of charge or electrons through a material.
An electric current produces a magnetic field.
Three Types of Particles
Protons- found in nucleus/the charge is positive (+)
Neutrons- found in nucleus/the charge is neutral
Electrons- found outside the nucleus/ the charge is negative (-)
3 Parts of a Circuit
Source- a battery
Resistor/Device- a light bulb
Path- a wire
Types of Circuits
Series have 1 path-1 goes out all goes out, more bulbs=dimmer
Parallel have multiple paths- 1 goes out all stay on, more bulbs= nothing happens
Voltage
Voltage is another name for potential difference
Voltage causes the current to flow
Voltage is measured in Volts or (V)
Current
Current is measured in Amps or (A)
Resistance
Resistance is measured in Ohm’s or (Ω)
Ohm’s=volts/amps
Resistance= volts/current
Different Signs
Volts-(V)
Amps-(A)
Ohm’s-(Ω)
Static Electricity
Static Electricity
Static Electricity is the build up of charges on an object
Repel and Attracts
Just like magnetism opposites attract and the similar repels.
How Charges are TransferredFriction- charges transfer when objects rub against each other
Conduction- charges transfer by direct contact
Induction- charges are rearranged or moved in one object while another is brought near
Static Discharge
Static Discharge is the loss of static electricity moving from 1 thing to another
The Law of Conservation of Charge
The Law of Conservation of Charge states that change can’t be made or destroyed.
Materials
Conduction
Conduction are materials that allow electrons to flow freely through them.
Some examples are metals, copper, iron, and water.
Insulators
Insulators are materials that hold on to their electrons, not allowing current to pass though well.
Some examples are rubber, glass, plastic, and wood.
Electromagnets
Solenoid
A solenoid is a current carrying wire surrounding an iron core.
Electromagnets
Electromagnets are useful because they can be turned on and off.
The Strength of an Electromagnet
The strength of an electromagnet can be increased by the number of loops, increasing the current, and having a stronger core.