Fleming's Left Hand Rule can be used to determine the direction of force on a wire carrying an electric current when placed in a magnetic field.
The magnetic field lines are always perpendicular to the direction of flow.
Magnetism is caused by moving charges or changing fields.
Electricity is produced from magnetism using electromagnets.
A generator converts mechanical energy into electrical energy using electromagnetic induction.
How to determine the direction of the magnetic field lines, by using the direction of the current?
Using the right hand thumb rule
4 ways to increase the magnetic field strength
increasing current
increase number of coils but keep the length the same
decrease length but keep number of coils the same
add and iron core
what would happen to the poles and magnetic field if the current was reversed?
The poles would switch sides and the magnetic field lines would flip around.
How can we reverse the magnetic field lines?
By reversing the current
Why would adding an iron core be beneficial?
It is a soft magnetic material. Which would gain magnetic field lines quickly and looses them as soon as current is switched off.
Order of Em waves :
radiowaves
microwaves
infrared
visible light
ultra violet
x rays
gamma rays
radio waves are made by oscillating changes
Radio waves are used for communication eg radio signals, bluetooth and tv
Short radio waves can be received at long distances from the transmitter. That is because they are reflected from the ionosphere.( an electrically charged layer in the Earths upper atmosphere)
Long radio waves can diffract around hills and tunnels
Medium radio waves can also reflect from he ionosphere, depending on its atmospheric conditions and the time of day
Micro waves are used by satellites and microwaves
Infrared radiation can be used to monitor temperature of objects.
the hotter the object the more IR it gives out.
absorbing IR radiation can cause an object to become hotter e.g food
Visible light is used to transmit data using fibre optic cables.
Ultraviolet radiation can give u a suntan and cause skin cancer
x-rays and gamma rays are used in medicines to see medical images and treat cancer