seeing what effect a magnet has on a compass. The arrows represent the north pole of the compass. Since the north side is repelled by the right side of the bar magnet this must be the north side.
Iron filings on a transparency mysteriously align to invisible lines of force around the bar magnet. Whyyyyyyyyyyyy!?!?!?!?!
These lines of force are being visualized with marker. Tried to use compass to trace these lines but the process was a little slow. For our purposes, this is a good enough approximation.
these red "2D Surfaces" are positioned in different ways. Because the 3rd surface wraps around both poles the circle goes in and out an equal # of times.
magnetizing a straightened paper clip
cutting the clip in half. The new magnetized pieces have north and south poles of half the strength
equating electric flux to magnetic flux.
showing that you can only go around an even number of magnetic poles. One cannot split a domain so a surface can only go around a positive and negative domain.
Because this is the case the magnetic flux is always zero.
an analog (not digital) oscilloscope. Proving that magnetic fields move the beam up and down and left to right.
showing where the electron will move with different magnetic fields. using left hand rule for negative charges in this case.
showing what happens when magnetic field and velocity are parallel
showing units for magnetism B= F/qV
calculation of force with known values of magnetism, charge, velocity and angle
getting acceleration from force with the mass of an electron
showing that electron will go in a spiral. This is a derivation for knowing the radius of the circle.
being given frequency one can find the magnetic field.
velocity of a positive charge can also be represented with current in the right hand rule. And the Force shows how the wire will move. Magnet creates a magnetic field.
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The set up
current must be going left to right since the wire moved down. (right hand rule). Though what is actually happening is that these spiraling electrons acting on the top of the wire which causes the lift.
same equation as before but with current.
showing how orientation in a magnetic field is important
showing that even though there can be no net Force there can be no net torque.
what will happen when a current passes through the loop.
chose C as we predicted
showing the relationship between length vector direction and torque
Today we learned about magnetic domains and how they make it so there is zero flux. We also saw how these wires can be coiled to make motors.
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