PHYSICS FOR FRESHMEN IN ELECTRICAL ENGINEERING

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1 PHYSICS FOR FRESHMEN IN ELECTRICAL ENGINEERING M.G.J. van Noord, P.H.F. Morshuis, M.D. Verweij, J.A. Ferreira, J.J. Smit and L. van der Sluis Faculty of Electrical Engineering, Computer Science and Mathematics Delft University of Technology Mekelweg 4, 2628 CD Delft The Netherlands Abstract The undergraduate curriculum at the faculty of Electrical Engineering of the Delft University of Technology has recently been reconsidered. In this paper an outline is given on how the introduction of a new physically oriented cluster with the courses Mechanics and Electricity & Magnetism creates a better connection between theory and practice. Further, the new curriculum gives a better overview of Electrical Engineering with the intention to motivate students and stimulate their self-learning process. Special attention is paid to classroom demonstrations and the introduction of a newly developed theme course, a project in which all first year students are faced with cases concerning different aspects of energy. The paper describes the clustering of the physics related courses and ends with a detailed description of a theme course. KEYWORDS: undergraduate course; electricity & magnetism; theme course; laboratory experience Introduction Electrical Engineering, the practical application of electricity, is based on mastering one of the four fundamental physical forces: the electrical force. One hundred years ago when Electrical Engineering started to bloom, the fundamental physical laws were clearly visible in the applications. The ability to build a solid mathematical framework on Maxwell s equations gave the opportunity to explore new areas and to develop new engineering concepts. For example, the lumped element representation and the network concept have boosted electronics and microelectronics. The drawback of a pure theoretical approach is that in the undergraduate electrical engineering curriculum less attention is paid to the phenomena that loom up by laboratory experiments and exploration of system components. The result of this, in combination with the rapid development of computer applications, is that hands-on and laboratory experience vanishes and computer simulations are getting more and more attention. To counteract these developments, the department of Electrical Engineering of the Delft University of Technology has aimed for a more attractive foundation course by creating a more easy to study undergraduate curriculum. The most important goals are: 1. Creating a better coherency in undergraduate courses by clustering related courses and thus decreasing their number. To emphasise the fact that all courses in a cluster are interrelated, integrated examination takes place for an entire cluster only. In addition, a shorter link with the knowledge obtained in secondary school is realized by moving basic courses like Electricity and Magnetism to the start of the undergraduate curriculum [1]. 2. Realising a better recognition of Electrical Engineering in the undergraduate curriculum, by introducing practical work that connects directly to the theory. In this paper it is discussed how a new cluster of the traditional courses Mechanics and Electricity & Magnetism has been formed, the way it is introduced in the new 1

2 curriculum and the consequences for the method itself and the results of examination. The recently introduced theme courses are outlined and an example of one of the theme course design projects is given. Mechanics and Electricity & Magnetism Four years ago the decision was made to make some fundamental changes to the course Electricity and Magnetism. This formerly second year course was taught by the department of Applied Physics, and was not well adapted to the needs of students in Electrical Engineering. It appeared that there was a missing link between the theory of the electric and magnetic field (culminating in Maxwell's equations) and the electrical phenomena that form the basis of the theory. The relevance of the theory was not clear at all to the students. Therefore, two changes were made to the course: 1. An inductive teaching method was chosen because experience has learned that this kind of method works best for the majority of Electrical Engineering students. The theory of Electricity and Magnetism (E&M) is taught by means of a phenomenological approach. Experiments and practical applications are shown in demonstrations as much as feasible, and subsequently the general theory is derived from this. 2. To enforce the link with practical electrical engineering applications a team of lecturers was put together from the Electromagnetic Research group and the High Voltage Technology group. Both have a considerable amount of experience in practical applications of E&M. In addition, the Electromagnetic Research group has a strong methodological tradition, and the High Voltage group has excellent facilities for demonstrations in their high voltage laboratory. The new method has proven to be successful and it was decided to use a similar method for the physically oriented cluster for first year students in the new curriculum, as mentioned in the introduction. This one-year cluster consists of Mechanics and E&M, and is taught by a team of lecturers from the department of Electrical Engineering and the department of Applied Physics. Figure 1 - A number of demonstrations was given on a 1:1scale in the High Voltage Laboratory. 2

3 Method The physically oriented cluster confronts students with physical phenomena and their mathematical description. The mathematical description of physical phenomena and the physical interpretation of mathematical equations are of primary importance in technical sciences. Integration of the two is usually difficult for undergraduate students. Because of the good experience with similar courses, the following method was chosen: In a week two to four one-hour auditorium lectures are given to explain concepts and basic theory illustrated with demonstrations and discussion of practical applications. In a week two to three hours of classroom exercises in groups of about 20 students are made. During these sessions the students are stimulated to be actively involved in tackling representative problems. The students are supposed to have studied the relevant topics. A staff member is present to elaborate (if necessary) on the theory presented in the lectures and to explain how to study. The relatively small group size allows for both an individual and a plenary guidance by the staff. Main objectives are to stimulate and to motivate the student in actively participating in the learning process. Each quarter all students perform an experiment with the objective to: o Generate and observe a number of physical phenomena o Get a feeling for the problems involved in performing an experiment o Learn to write down all relevant data in a report Prior to the experiments the students learn about safety and measurement inaccuracy. Figure 2 - Experimental demonstration of high-temperature superconductivity: a small magnet floating above a piece of superconducting material cooled by liquid nitrogen. Examination As follows from the introduction, in the new first year curriculum the student no longer gathers credit points for each single course. Every four weeks the students participate in a partial examination. These examinations are meant to show the students whether they are well on course and have sufficient command of the subject 3

4 matter. Further these form the basis for the determination of the overall credit point for the cluster. To stimulate a continuous learning process, the students are only informed whether they score sufficient or insufficient. The fourth and eighth (last) examination consist of two parts, a part that relates to the topics studied in the four weeks prior to the examination and a cumulative part covering all topics dealt with up to then. If necessary, this last part can be used for a second opinion on the cumulative knowledge of the student. The student will pass the overall examination if the average score of the in total eight examinations is sufficient or if the results of the cumulative part of the eighth examination are sufficient. Results Because this year s course has not finished yet, no final evaluation of the results can be given. Last year the results improved impressively and the majority of the students passed the examination, especially those who participated in the training sessions. The course, like any other course, was also evaluated by the students. The phenomenological approach and the training in small groups were highly appreciated. There was some discussion on the amount of contact hours between staff and student. In the end, however, most students agreed that they benefited from the training and would rather not do without it. Theme courses Telecommunications, Information Technology and Microelectronics are nowadays dynamic topics, and often students already have an idea of these subjects before they start their study. Electrical Power Engineering usually copes with a non-dynamic image and is hardly recognised in daily life. One of the challenges of the theme course Electrical Power engineering is to show that many interesting things take place in power engineering, technical and economical [2]. The latest technical developments have a great impact on society, but also liberalisation of the market and economical optimisation of the power system raise a lot of interesting research topics. As such the theme courses make the students familiar with one of the technological main streams in the department of electrical engineering and is therefore an important part of the first year curriculum. The theme course about energy was a great success in practically applying the previously gained theoretical knowledge on relevant aspects of electrical energy and is taught by the staff of the Electrical Power Systems Laboratory, the Electrical Power Processing Laboratory and the High Voltage Laboratory. From each laboratory topics appear in the course. The course starts with an overview of different aspects like recent- and future developments with the emphasis on renewable energy resources. Within four weeks groups of approx. 10 students have to design and build an electrical train system or a pumping system. During the designing process, the teamwork and activation of the students is of major importance. Finally the students have to build a working system. To motivate the individual groups, a competition element is introduced: the group with the best system performance is declared to be the overall winner. In the next paragraph the train system will be highlighted. 4

5 Figure 3 A group of students; each student participates actively during the designing phase of a theme course. Energy theme course: A durable electrical train system One of the cases in the theme course about energy is the design and implementation of a durable railroad connection in the mountains for the transportation of goods. Boundary conditions of this scale model system are that electrical energy is only available at the beginning and at the end of the railway. Uphill a renewable solar plant could be build or the existing, relatively weak power system can be used. Downhill a complete new power substation might be build. In this case the storage of electrical energy is unavoidable and students have to figure out the optimal solution and configuration based on technical, economical and environmental considerations. Finally, system calculations on efficiency, system dimensions and overall performance have to be verified with the system that has been build. Because the implementation is a scale model, as shown in Figure 4, the measurements of parameters like voltage, current, power and time can safely and easily be performed. Important in the design process is that the students always have to make a link with reality, e.g. in a solar- or wind system they must realise that the amount of sun and wind changes continuously during the day. These aspects have to be considered carefully and form a part of the final evaluation, just like the path of the process, the level of knowledge, creativity, enthusiasm, and of course the performance of the system. 5

6 Figure 4 Freshmen testing their design of a durable railroad connection in the high voltage laboratory Conclusions The changes in the undergraduate curriculum at the Department of Electrical Engineering at the Delft University of Technology seem to be successful so far. The clustering of the physically oriented courses Mechanics and Electricity & Magnetism (E&M) and in combination with a new, more inductive form of education make the course more attractive and easier to study. Experiments create the connection of theory and practice, while classroom exercises help students to apply their theoretical knowledge. This new method of education requires also an adaptation of the examination method. Credit points are no longer collected with stand-alone courses but are the average of eight successive partial examinations. Up till now, the results of this educational method suggest an increase in the number of students that pass the final examination. The newly introduced theme courses give the students the opportunity to get a better insight in the different fields of in power engineering in particular and of Electrical Engineering in general. This plays an important role on the link between theory and practice, and stimulates the motivation and active attitude of the students. References 1. F.T. Ulaby and B.L. Hauck: Undergraduate Electromagnetics Laboratory: An invaluable part of the learning process, Proceedings of the IEEE, p.p , Vol. 88, No.1, january Power engineering Education Committe: Electrical Power Engineering Curricula content in the 21 st century, IEEE Transactions on Power Systems, pp , Vol. 9, No 3, August