Flashcards in magnetisim Deck (31):
Two types of magnetic poles:
North and south
As with electric charges, like poles (n&n) (s&s), _ while n&s _
Can you have only a north or south pole?
Are magnetic poles electric charges?
which way do magnetic field lines point?
north to south
Geographic North pole is
magnetically x ; that
is why magnetic north
part of compass points
Geographic South pole is
magnetically x; the
is why magnetic south of
If a charge is moving across the magnetic field,
the charge will feel sideway force
If a positive charge is near permanent magnet,
no interaction between stationary charge & magnet
what happens to electric charge in a magnetic field
the current will field a sideway force in the magnetic field
signal from amplifier is fed to coil which sits inside a magnetic field created by permanent magnet
speaker: the electric current in the coil will experience force & that results in
the diaphragm vibrate, vibration of air, production of sound
The universe is a shooting gallery of charged particles.
Most of this radiation on earth comes from the Sun and they are hazardous to life.
Fortunately, most of these moving charged particles are deflected away by Earth’s magnetic field. Some of them are trapped in Earth’s magnetic field. Trapped particles interact with atmosphere and cause it to glow like fluorescent lamp
how do birds know where to fly?
biomagnetism- certain bacteria form internal compasses, so birds have internal compasses. they have magnets in their skulls and can discern magnetic field direction along earth's b field.
By winding many turns, the magnetic field is made proportionally x.
larger. By winding turns along cylinder we get a coil, with magnetic field just like a bar magnet! electromagnetism
Where is current in a bar magnet aka a permanent magnet?
circling around nucleus. current is in a loop. each atom is tiny magnet
what is the earth's magnetic field like?
We don’t know exactly why earth is a
magnet. Earth’s magnetic field looks like a
strong bar magnet. But earth is not a
magnetized bar magnet because it is simply
too hot for individual atom to hold a proper
what do scientists think about earth's magnetic field?
Many scientist speculate that electric
currents are the result of convection
currents-from rise and fall of magma
combined with the Earth’s rotation
changing e field creates magnetic field
changing m field creates electric field
faraday's law: When loop is rotated in magnetic field
current is generated in the loop. –Instead of
moving magnet rotate loop !
Induced current (electromagnetic induction) in coil is generated by changing B field nearby coil. You can achieve this by
moving the magnet
change the current in the nearby coil
oscillating electric field and oscillating magnetic field;
Regenerate each other!!
Oscillating Electric Field induces Oscillating Magnetic Fields. (Ampere’s Law)
Oscillating Magnetic Fields induces Oscillating Electric Fields
Frequency: # of vibratiions per unit of time made by the vibrating source
# of vibrations per unit of time made by the vibrating source
distance between adjacent crests
Longest to shortest wavelength:
radio waves, microwaves infrared, visible light, ultraviolet, x-rays, gamma rays