Direct Current Electrical Circuits Research Articles

Effect of Conceptual Change Oriented Instruction on Students’ Conceptual Understanding and Decreasing Their Misconceptions in DC Electric Circuits

The purpose of this study was twofold: first to investigate the effect of conceptual change oriented instruction accompanied by concept cartoon worksheet with simulation on students’ conceptual understanding and second to remedy their misconceptions of direct current electric circuits. Participants were 139 pre-service science teachers from four intact classes. A quasi-experimental design was used in the study. The experimental group studied the concept with the application of concept cartoon worksheet and simulation, and the control group studied it with traditional instruction. Students’ conceptual understanding and misconceptions were measured by a tree-tired misconception test. It was administered as pre-and-posttest. There was no significant difference between the means of pre-test scores of experimental and control groups. The main effect of treatment on post-test scores was examined via ANCOVA with pre-test scores used as covariate. The frequency of each misconception was calculated for both groups, from pre to post-tests regarding all tiers of items. The analysis yielded a significant treatment effect on students’ post-test performances. The findings indicated that the conceptual change oriented instruction accompanied by concept cartoon worksheet and simulation is likely to be effective for conceptual understanding and decreasing most of students’ misconceptions in direct current electric circuits.

Design and implementation of a remote laboratory platform using MATLAB builder for NE

ABSTRACTIn this study, a highly instructive and novel remote laboratory platform using up to date software and hardware units is designed to teach main concepts of Electrical Engineering with the help of web‐based simulations and remote accessible experiments in real time. Interactive experimental applications for direct current (DC) motors and several electrical circuits are carried out in this study to test the efficiency of the system. First, mathematical model of each simulation is developed in MATLAB and then all models are transferred into .NET platform by means of MATLAB Builder for NE toolbox. A dynamic library for each model is also created using NE toolbox. Then, all libraries are embedded into an interactive web page designed in ASP.NET platform. Data transmission between the server and the real experimental set is established by a microprocessor via the USB port to achieve the experimental studies over the Internet in real time. While remote experiments are being performed, data obtained by the experimental set are simultaneously transferred to the MATLAB. Then, the system generates both graphical and numerical results about the current experiment and all results are sent to a user‐friendly web interface to give users some feedback on the experiment.© 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:617–629, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21553

Effects of Conceptual Change and Traditional Confirmatory Simulations on Pre-Service Teachers’ Understanding of Direct Current Circuits

The objective of this research is to investigate the effects of simulations based on conceptual change conditions (CCS) and traditional confirmatory simulations (TCS) on pre-service elementary school teachers’ understanding of direct current electric circuits. The data was collected from a sample consisting of 89 students; 48 students in the experimental group who were taught simulations based on CCS, and 41 students in control group who followed the TCS. Subjects in both groups used open source software (Qucs) to simulate electric circuits. All students were administered Electric Circuits Concepts Test (DIRECT), Science Process Skills Test, Physics Attitude Scale, and Computer Attitude Scale before the treatment. Pre-test analyses revealed that there is no significant difference between experimental and control groups in terms of understanding of direct current electricity. After completing 3 weeks treatment, all students received the DIRECT again as a post-test. Analysis of covariance was used. Science process skills and attitudes toward computers were taken as covariates. The results showed that the conceptual change based simulations caused significantly better acquisition of conceptual change of direct current electricity concepts than the confirmatory simulation. While science process skills and attitudes towards computer made significant contributions to the variations in achievement, gender differences and interactions between gender and treatment did not. Eleven weeks later, the DIRECT was reapplied to the students in both groups. Eleven weeks delayed post-test results showed that the experimental group outperformed the control group in understanding of direct current electric concepts.

Students’ understanding of direct current resistive electrical circuits

Both high school and university students’ reasoning regarding direct current resistive electric circuits often differ from the accepted explanations. At present, there are no standard diagnostic tests on electric circuits. Two versions of a diagnostic instrument were developed, each consisting of 29 questions. The information provided by this test can provide instructors with a way of evaluating the progress and conceptual difficulties of their students. The analysis indicates that students, especially females, tend to hold multiple misconceptions, even after instruction. During interviews, the idea that the battery is a constant source of current was used most often in answering the questions. Students tended to focus on the current in solving problems and to confuse terms, often assigning the properties of current to voltage and/or resistance.

Manipulating parallel circuits: the perioperative management of patients with complex congenital cardiac disease

In all patients undergoing cardiac surgery, the effective delivery of oxygen to the tissues is of paramount importance. In the patient with relatively normal cardiac structures, the pulmonary and systemic circulations are relatively independent of each other. In the patient with a functional single ventricle, the pulmonary and systemic circulations are dependent on the same pump. As a consequence of this interdependency, the haemodynamic changes following complex palliative procedures, such as the Norwood operation, can be difficult to understand. Comparison of the newly created surgical connections to a simple set of direct current electrical circuits may help the practitioner to successfully care for the patient. In patients undergoing complex palliations, the pulmonary and systemic circulations can be compared to two circuits in parallel. Manipulations of variables, such as resistance or flow, in one circuit, can profoundly affect the performance of the other circuit. A large pulmonary flow might result in a large increase in the saturation of haemoglobin with oxygen returning to the heart via the pulmonary veins at the expense of a decreased systemic flow. Accurate balancing of these parallel circulations requires an appreciation of all interventions that can affect individual components of both circulations.

Macroscopic phenomena and microscopic processes: Student understanding of transients in direct current electric circuits

Studies of student understanding of simple electric dc circuits have shown that many of them find it very difficult to apply qualitative reasoning to explain the observed phenomena. It has been suggested that these difficulties may be due to their failure to construct models of microscopic processes that lead to these phenomena. Indeed, in the traditional courses, such models have generally not been emphasized. In the present study, we compared the performance of different groups of university students in answering a questionnaire designed to probe their understanding of the relationship between macroscopic phenomena of transients in a dc circuit and the microscopic processes that can explain these phenomena. One group studied from a traditional text, the second group used a recently developed text that emphasizes models of microscopic processes. We also conducted detailed interviews with some of the students. From an analysis of the performance of these two groups, and also from a comparison with a previous study on Israeli high school students, we found that most of the students whose instructional experiences included an emphasis on the development of models of microscopic processes developed a better understanding of the transient phenomena studied. They applied qualitative considerations in their analyses and were able to develop coherent models to describe their observations. Overall, they demonstrated a superior understanding of the physical phenomena.