5/7 Magnetic Fields

We were asked to draw arrows that indicated the direction of the magnetic field at different points on this metal bar.

This is our representation of how the magnetic field looks around the metal pole. We found that we could use our old formulas that had Electric Field in it and replace it with a new variable B, the magnetic field and we could replace charge, q, with the number of poles, p, . Our old formula with electric field is charge / epsilon but since the net amount of poles in the magnetic field is 0, we can say that the integral of BdA = 0.

This is a visualization of how the magnetic field behaves around the metal bar. We see that the magnetic field looks like the patterns on a pumpkin except on the top and bottom where the arrows don't circle back to the metal bar and keep going.

We were asked to make a prediction of how the piece of metal in the middle of the magnet would behave once it was charged. We found that it didn't matter if the charge was negative or positive, only the direction of the current mattered. 

We were given a problem that asks what the force is on each direction of the metal plate if it lies on the xy-plane and a magnetic field is going straight through it on the z-axis. We found that since the magnetic field is perpendicular all force vectors on the metal plate, the net force was 0N.

We derived a formula to find Force and found that force = qV x B. Since we know that current = charge / time and velocity= length / time, we can interchange q and v with I and L depending on the given information. 

This is an example of how a Cathode Ray Tube behaves when their is a strong magnetic attraction/repulsion near the tube. Because the magnetic force from the magnet is strong, the electrons inside the tube are attracted/repelled toward/away from the magnet. Originally, the green dot was at the center of the screen but because of the magnet, it has shifted slightly to the left.

We draw a diagram of how the inside of a Cathode Ray Tube works and found the resultant force vector if there were a magnetic field being directed at the electrons from a certain direction. We used the right-hand rule to determine the direction of the force and found the dots displacement if it started at the center of the screen.

We were given a problem to find the acceleration of a proton in a magnetic field with the given information. 

This is 2 different problems that we were asked to find the force of. In red, the metal plate is parallel to the direction of the magnetic field and we found that the force on the top and bottom were 0N and the force on the left and right canceled each other out resulting in a net force of 0N. In green, we were asked to find the torque of the metal plate if the magnetic field is going through the z-axis and the plate lies in the xy-plane. We found that the force on the left and right were 0N and the force on the top and bottom were going in opposite directions. This caused the plate to spin clockwise. 

We were given a problem that asked what the different forces were at 15 different segments of a half circle. We were given the radius, magnetic field, and the current. We found that at the rightmost and leftmost parts of the half circle, the force was 0N and the force is greatest at the center. This makes sense because the magnetic field is tangential to the force vector at the left and rightmost points and is perpendicular at the center.