Today we start out by creating another paperclip magnet and we attempted to destroy it by heating it up.
We noticed that after heating up the paperclip...it still works.
More heat? Not enough.
Okay, magnet bork.
A picture of the paperclips atoms before and after being magnetized, When magnetized, the atoms align with the magnetic field and therefore create their own.
Below, we have the potential ways we could destroy a magnet, adding lots of energy or just giving it a big shock.
Here we have a nicely coloured practice problem with current and magnetic fields again. Given a constant magnetic field and the direction of the current, we can find the resulting forces because of it.
We can also find the net torque and since the angle is perpendicular, the cross product can just be magnitudes.
We define the magnetic dipole moment to be the number of loops times current times the are, and we set the torque equal to a function of the dipole moment. Since there was a sine component, we define it to bet he cross product.
Below is an example problem using the formula.
The inner working of a brushed motor. There are coils and the current passes through the brushes to push the motor.
Since there is a lot of movement in the motor, the two most likely things to break in the motor are the commuter and the brushes.
Since the commuter passes the current and the brushes allow current to pass to the commuter, if either one fails from too much wear, the motor stops working.
Given this loop, we calculated the net torque acting on the system.
Here we give the a motor a push to get it started.
The brushed motor consists of two magnets creating the magnetic field and two loops which are powered by the brushes interacting with the commuter.
Once going, the potential from the power supply keeps the motor going.
Now it's time to make our own, we begin our ghetto motor by wrapping some wire around an empty Starbucks branded coffee container.
Then we secured the coil in place and made some ghetto stands for the coil.
Taping them down and putting the magnet beneath it, we sanded one wire completely and half of the other wire so we would have a force only half the time in order to push the motor.
The ghetto motor worked fine.
Examining the torques on a motor coil, we find which direction the motor will turn based on the direction of the current.
Here we have a symbolic definition of current with electron density, charge, drift velocity, and area.
Substituting in for the area:
We equate the electric field to the Hall Voltange divided by angular frequncy.
Solving for the angular frequncy, we can find the area that it coves over time t.
Now since current is writeen in terms of the Hall Voltage, we can solve for it.
- Other group's since I lost mine -
When a current is passed through a conducting path, there is a magnetic field associated with it. The person credited with the discover is Michael Faraday who discovered the properties of this magnetic field.
With current passing through the rod, we can see the compasses align with the magnetic field generated by the current.
Our prediction, which was "way wrong".
The current passing through the opposite direction, which in turn reversed the magnetic field.
With a wire hooked up to a board, we can see the magnetic field along any point in the circuit.
The fields behave how we thought, with some canceling out or strengthening other due to the placement of the wires and the current flowing through them.
An overview of the circuit.
Here we can see that if we substitute into our equation for the magnetic field with the permeability of free space, we can see that charge times velocity is the equivalent of current times differential length.
Relating the two forces based on the permeability and permittivity of free space, we can find that multiplied together, they are the inverse of the speed of light squared. With the forces, the ration happens to have most things cancel and we are left with a ratio of velocity squared and the speed of light squared.
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