day 22

top is an equation on how magnetic field is related to the condition of the wire. The equation is then inserted into the force due to a magnetic field on a wire equation.

same thing here

these are copper wires with current going in the same direction.

these are power lines with currents going in opposite directions. These are forced outward

graph of a compass being spun around from north to south to north at constant rate

had copper wire coiled in a test tube and used a magnetic field reader to see the strength of the field compared to how many time the wire is coiled

this is showing under what orientation the plate has maximum and minimum flux

the current generator we used for the coil experiment

when the professor moved the magnet in and out of the copper coil. It created a change in flux and induced a current

variables we assumed would magnify the change in current.

when the # of coils increased so did the spike in current.

the copper ring floated because it induced a current and this created an opposing magnetic field that repelled the coil from the ring

same with a aluminum ring even though it is non-magnetic

our explanation

our explanation on the first demonstration and why it worked. *An open loop will not work because it does not have a closed circuit to facilitate the current, nor does it have capacitance to facilitate current temporarily.

metal conductive objects slowly move flow through the tube

our diagram showing how the back emf is created.

equation for back emf.

shows how emf is really related to the change in flux through area and magnetic field.

this is a change in magnetic field effects emf with a change in time

Day 21

our group showing magnetic domains must be positioned in a metal that is made to be magnetic.

how to eliminate magnetism in a metal object that is magnetic.

mason is magnetizing a paperclip

after heating the paper clip, it is no longer magnetic.

no current through the pole

prediction when current is out of the box

prediction was verified

our predictions for what happens when magnetic fields interfere with each other.

showing how when the current carrying loop is in a magnetic field that the net force is always zero but that the net torque can still be something like in this case where the angle is 60 degrees.

showing the equation for torque.

showing how the torque is related to the angle of the plane

our calculation of the torque given the magnetic field, area, and the current

if myoo is equal to the NIA then torque equals myoo cross B.

magnets create a magnetic field and and the coils of wire carry current. The pole in the center is allowed to spin but not mov.

each time we changed the current, it spun the opposite way. When the magnetic field was flipped then the spin also changed. when both were changed the direction of the spin remained the same.

how we assumed the motor might degrade over time.

just the set up

a simple motor we created in class. The wire was coiled around a test tube and were tied to retain its shape. The insulating coating was stripped completely on one side and only half on the other side. This allowed the current not to flip, but for it to stop on half of the turn so the momentum could carry it forward.

determining equation for hall voltage

how gear speed is monitored in a car. The teeth of the gear change the magnetic field through the hall sensor, and the car can read the change in current. The waves tell the care how fast the gear is rotating.

equation for the relationship between the electric force and magnetic force in current carrying wires.

Today we had an introduction to magnets and how they are made up of a large FINITE quantity of tiny (magnets) called magnetic domains. When something is magnetic these domains are lined up. Magnetism is linked to electron spin however we did not get too much into that. We then saw how non-permanent magnets lost their charge and the professor demonstrated this phenomenon practically. We then looked at how current carrying wires can produce an electric field and how this is the basis for electric motors.