Pre-service physics teachers’ mental models about the electric field

Author(s):  
Tuğbanur DİNÇER ◽  
Ozgur Ozcan

Abstract This paper identifies pre-service physics teachers’ mental models of the concept of the electric field. The models were determined by means of five contexts all of which were supported with sets of experiments. The contexts examined were (1) the effect of the electric field on the insulator, (2) the comparison of the conductor and insulator in the electric field, (3) the effect of the electric field on the neutral conductor and insulator, (4) the effect of the electric field on the conductor liquid, and (5) the effect of the conductor and insulators materials forming a closed surface on the electric field. Semi-structured interviews related to the contexts were conducted with the 22 pre-service physics teachers. The data collected throughout the interviews were put to content analysis and thus, the pre-service teachers’ mental models were identified. In total, six mental models were identified. One model was a scientific model (Scientific Model of the Electric Field (SMEF)) and five of which were unscientific models (Magnetic-Based Field Model (MBFM), Mechanical Wave Model (MWM), Material Independent Field Model (MIFM), Force-Free Field Model (FFFM) and Force-Based Field Model (FBFM)) were identified. It became apparent as a result of document analysis that several unscientific mental models were also included in resource books. Approximately one and a half years later, almost all students were interviewed again about the contexts so as to find whether or not their models were permanent or not. Following the interviews, their mental models were found to be quite permanent and to be time-independent.

2016 ◽  
Vol 17 (4) ◽  
pp. 743-755 ◽  
Author(s):  
Nilüfer Didiş Körhasan ◽  
Lu Wang

Mental modeling, which is a theory about knowledge organization, has been recently studied by science educators to examine students' understanding of scientific concepts. This qualitative study investigates undergraduate students' mental models of atomic spectra. Nine second-year physics students, who have already taken the basic chemistry and chemistry laboratory application courses, participated in the study. Semi-structured interviews were conducted with the participants. The analysis revealed that students had four types of coherently organized knowledge structures: the Scientific Model of Atomic Spectra (SMAS), the Primitive Scientific Model of Atomic Spectra (PSMAS), No Photon Model (NPM), and the Orbit Model (OM). Identified mental models indicated that students used some fundamental concepts interchangeably, and “electronic transition” and “photon energy” were the threshold concepts for students' scientific understanding of atomic spectra.


2018 ◽  
Vol 38 ◽  
pp. 04004
Author(s):  
Feng Huang

disintegration examination and analysis are employed in flexible terminal breakdown of 110 kV XLPE insulated cables. It is considered that the main reason of breakdown is the separation of the stress cone of the terminal and the fracture of the semi- conductive layer of the cable insulation. Therefore, the finite element method is used to electric field model and simulate the dislocation fault of internal stress cone and outer semiconductor layer of cable insulation. The distribution of the electric field intensity is calculated and compared. The simulation and calculation results verify the validity of the breakdown mechanism analysis, and put forward some practical suggestions.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Changping Li ◽  
Longchen Duan ◽  
Songcheng Tan ◽  
Victor Chikhotkin ◽  
Xiaohui Wang

Electropulse rock breaking has wide application prospects in hard rock drilling and ore breaking. At present, there are no suitable physical mathematical models that describe electropulse boring (EPB) processes under confining pressures. In this paper, a high-voltage electropulse breakdown damage model is established for granite, which includes three submodels. It considers electric field distortions inside the rock, and an electric field distribution coefficient is introduced in the electro-breakdown model. A shock-wave model is also constructed and solved. To simulate the heterogeneity of rocks, EPB rock breaking in deep environments is simulated using the two-dimensional Particle Flow Code (PFC2D) program. The solved shock wave is loaded into the model, and confining pressure is applied by the particle servo method. An artificial viscous boundary is used in the numerical simulation model. Using this approach, a complete numerical simulation of electropulse granite breaking is achieved. Breakdown strength and the influences of physical and mechanical parameters on it are also obtained. Time-varying waveforms of electrical parameters are obtained, and the effect of confining pressure on EPB is also described.


1996 ◽  
Author(s):  
Dominic M. Zarro ◽  
Richard A. Schwartz

2014 ◽  
Vol 716-717 ◽  
pp. 876-879
Author(s):  
Xiao Bei Wang ◽  
Li Xia ◽  
Xiang Jun Wang ◽  
Dou Ji

The underwater electric field model of spherical sensor is established. According to the condition that boundary condition is some certain eigenvalue, affects on underwater electric field by spherical sensor is derived. At last, the underwater potential distribution around spherical sensor is calculated through numerical calculation method.


2004 ◽  
Vol 82 (7) ◽  
pp. 541-548
Author(s):  
D.G.C. McKeon

Antisymmetric tensor gauge fields ϕab(η) are formulated on the surface of a sphere S4(η2 = a2) embedded in five dimensions. Such compact manifolds occur in the dimensional reduction of higher dimensional spaces that naturally occur in string theories. The free field model is equivalent to a scalar model on this sphere. Interactions with gauge fields are discussed. It is feasable to formulate models for interactions with U(1) gauge fields Aa(η) that are akin to those of Freedman and Townsend in flat space. In addition, it proves possible to have a novel interaction of ϕab with Aa and a spinor field Ψ(η) on S4 with both Abelian and non-Abelian gauge invariance. In these models, Aa plays the role of a Stueckelberg field.PACS No.: 11.30.Ly


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