Student "edition" found at {csi dot journalspace dot com}.

Maybe I shouldn't have started this blog now, not with everything that's been going on.

In the second meeting of my Introduction to Electricity and Magnetism class for the thirteenth week of the first term, the last meeting of the subject, we had to hold it in the robotics lab, the scene of their practical exam for half of them afterwards, since the previous class in the same room (a business course) was still not finished yet with the defense of the students in front of four teacher panelists.

It was the secretary who had to inform me of the move, but seeing that all the classrooms were being used at that time except for the one on the basement, I opted for the engineering lab instead, just one floor down, even though it did not have enough seats for my almost thirty students.

I discussed the mathematical method of getting the resultant vector of the cross product without having to resort to the right hand rule which some of them find confusing. Instead they could use the three by three matrix first learned in their Intermediate mechanics one class, which gave the direction as the three dimensional coordinate that can also be used as the coefficients of the unit vectors in the form of an equation.

For the torque of a loop of current in a magnetic field, the normal to the area along a certain plane had to be obtained, and for this I used the same method we had in Engineering Materials Science class of taking any three points, getting the two lines associated with two pairs from the points and getting the cross product of that, automatically perpendicular to the plane the two lines are included in.

This was the only example where they had to use the cross product twice, once to get the vector of the magnetic dipole moment that is in the same direction as the normal to the area, and another time to get the torque.

We were supposed to use the same for the magnetic field from a straight wire and maybe an arc, but there wasn't enough time, so I had to tell them they had to rely on the right hand rule for that part, and that part only.

Thus ends another term of INTELMA, where I got to take up all the topics I wanted, not less, with some additional topics thought of for next time.

Session 1267 has to use hands to get direction. Class dismissed.