Magnets and Electromagnetism

what type of force is magnetism

non contact

where are forces on magnets strongest

near the poles

what are the ends of magnets called

north and south poles

which poles repel and attract

like poles repel and opposite poles attract

magnetic materials

no force between them but attract to the poles of magnets

how do you make a field stronger

increase the current and add additional waves

how can you see how strong a field is

the weaker the field the further away the field lines are

what is the magnetic field of a solenoid like

inside the solenoid the field is strong and uniform but around the solenoid the field is similar to that produced by a bar magnet

how do you increase the strength of a solenoid

add more turns and increase the current and add an iron core which turns the solenoid into an electromagnet

when current flows in an external magnetic field what happens

it experiences a force because the magnetic field around the wire interacts with the external magnetic field

what does the size of a force experienced in an external magnetic field depend on

the amount of current and the length of wire

how can magnetic field strength be increased

by using a stronger magnet or by moving the two magnets closer together

how can you change the direction of the force experienced in an external magnetic field

change the direction of the magnet or change the direction of the current

what is the equation for force magnetic field current and length of wire

F=BIL so force N - magnetic field J x current A x length of wire inside magnetic field m

what is the FBI method

dot means going out and cross means going in and magnetic field is always from north to south

what does frequency effect of a sound

pitch

what does amplitude affect of a sound

volume

how does a loudspeaker work

when current flows through the coil it creates a magnetic field and the magnetic field from the wire interacts with the magnetic field of the permanent magnet which produces a force on the wire. when the ac current in the coil changes direction the force changes direction and this causes the coil and hence the cone to vibrate which produces a sound wave consisting of peaks and troughs