Day20

Magnetic Fields:

By using a compass, we can find the direction of a magnetic from a bar magnet, North is attracted to South, and south is attracted to north, too.  Drawing the direction by compass.

 Gauss's  Law in Magnet is defined as ∫B∙dA. ∫B∙dA=0 because there is no monopole, in every single magnet, there will always be south pole and north pole. Thus, the net flux is always zero. 

  Electric Field Lines:
After using compass, we spray some Fe power near a magnet to see the magnetic field. Magnetic fields go from positive to negative. 

Lorentz Force

Lorentz Force Large Magnet Demo

For this lab, Professor Mason shows out a large magnet and set up a copper wire across and in between the magnet.

When we give the current, we found the copper wire jump down, but when we change the direction, the copper wire jump up.

The velocity of the electrons is going through the wire, the direction of the magnetic field is going across the poles of the magnet, and the force is perpendicular to the velocity and magnetic field (Lorentz Force= F=qVxB or F=qvBsinθ).

 Finding Net Force

we find the total force on a wire by using a spreadsheet. (F= IL x B) It can be observed that there is a maximum first at 90 degrees and a minimum on the sides.