Electromagnetism is a subject many find very abstract and difficult to grasp. Associate Professor Samel Arslanagic has devoted much of his working life to introducing students to the world of electromagnetism.
A distinction is made between four natural fundamental forces: gravity, electromagnetic force, and strong and weak nuclear energy. Nuclear energy only works inside the atom, which is why we do not feel it in our everyday lives. Gravity, on the other hand, is very obvious to us.
Electromagnetic force is evident both in mechanical forces such as normal force—which keeps objects from sinking through tables—and the chemical forces that bind molecules together.
All matter consists of positive and negative charges creating electrical and magnetic fields around them. Together, they form electromagnetic fields that, in the world of mathematics, are represented by vectors. They have both a size and a direction and exist in a three-dimensional space, and they can be hard to visualize. We can see very high frequencies such as light, which is also an electromagnetic field, but we will have to settle for imagining radio waves, microwaves, etc.
Fig.: The magnetic field surrounding a current in a conductor.
The mathematics is therefore a little more abstract than usual, and electromagnetism is a subject feared by many—including Samel Arslanagic when he was a student. And since he started teaching about 11 years ago, he has worked hard to fine-tune his teaching methods. He has succeeded so well that he was named Lecturer of the Year in 2018, and the course is now one of the most popular DTU courses.
“You need to be able to explain the basics in your sleep”
Samel began teaching as a PhD student and has now taken over all 26 lectures on the course, which is mandatory for Electrical Engineering students, but is also taken by many in the Earth and Space Physics and Engineering programme.
“By now, I think I’ve read nearly all important books on electromagnetism. You not only have to be passionate about the subject, you also need to have a thorough understanding of it, so that you can explain the basics in your sleep. And I make a point of showing how the physics and mathematics are linked,” says Samel.
“It’s so important to motivate and involve the students. That’s why I make a point of telling them what they can use their knowledge of electromagnetism for. For example, I’ll show them some examples that they may have already seen in school, but which they’ll now get the full electromagnetic understanding of. By giving them these kinds of aha moments, I’m involving them in the teaching so they can find the calculation methods and answers on their own.”
Video tutorials an important tool
Samel is very aware of the fact that his way of explaining things might not be the best for all 100 students, and everything within the field of electromagnetism can be explained in several ways. And he does not have the time to go through every detail of each example during a lecture. Therefore, he has made numerous video tutorials in which he uses illustrations to show how to solve various problems.
“For example, with a power distribution you typically want to calculate the magnetic field around it,” he explains.“In the video, I start from the top and explain how to set up the model. Once you understand that, you can usually solve the problem using mathematics.”
Fig.: Plane electromagnetic waves, which can propagate even in empty space. They have both an electric field (E) and a magnetic field (H), and they are oriented as shown in the figure.
So far, Samel has solved 20 tasks about fundamental electromagnetism in videos lasting about 10 minutes each, and soon there will be 10 more. In addition to this he will provide short video recordings of lectures in which he summarizes each course topic in 30 minutes.
Do the students even need to show up for the lecture?
“Yes, because the motivation comes from the direct interaction between lecturer and student. It matters that you’re face to face and looking them in the eye while you explain things and perhaps make a joke every now and then or a funny remark or compare electromagnetism with something else. I gets them interested and makes them want to come back,” says Samel, adding:
“The traditional, and perhaps slightly old-fashioned, activities such as the chalk-and-talk method and direct interaction with the students are still absolutely indispensable, even today, when everything is easily available online.”
The videos are therefore a supplement that can be used when you are at home and in doubt about something. They are available on Samel’s YouTube channel. In this way, they are also available to other students and educators around the world.
In 2018, Samel Arslanagic was named Lecturer of the Year at the BSc Eng programmes for the courses Electromagnetics and Wireless Communications.
He has also twice been named Teacher of the Semester at DTU Electrical Engineering.