Development of a hardware-software system for the experimental study of the ferromagnetic groove carrying conductor surface
The paper presents the results of an experimental study of the ferromagnetic groove electromagnetic field based on a developed laboratory bench equipped with a hardware — software measuring system. A technique for determining the current density in the conductor cross-section by measuring the magnetic field induction when immersing two types of sensors (frameless fine measuring coil and Hall sensor of a digital millislotometer) has been implemented for various depths inside the groove. The use of a measuring coil as a sensor makes it possible to obtain the current density distribution over the conductor height through the procedure of integrating the voltage proportional to the EMF induced in the measuring coil using a LabVIEW environment-built in a digital integrator. Measurement of magnetic field induction by the Hall digital sensor at a laboratory bench provides the measuring coil verification and the reliability of the experimental study results determination. With the help of the hardware-software complex, a distribution of the current density and magnetic induction along the conductor height in the ferromagnetic groove is obtained at a laboratory bench. The results of an experimental investigation of the surface effect are compared with the results of calculating the alternating magnetic field of a conductor with a current in a ferromagnetic groove in the Elcut 5.6 program complex. The active and the inductive conductor resistance at the industrial frequency are determined.
Chapter 12 – Data Acquisition with LabVIEW
This chapter introduces the reader to the concept of computer-based data acquisition (DAQ) and to LabVIEW, a software package developed by National Instruments that is used extensively in laboratory settings. The main reason for focusing on LabVIEW is its prevalence in both academic and industrial settings. LabVIEW is an extensive programming platform and includes a multitude of functionalities ranging from basic algebraic operators to advanced signal-processing components that can be integrated into rather sophisticated and complex programs for use in laboratory (and even industrial setting). For pedagogical reasons, we will only introduce the main ideas from LabVIEW that are necessary for functioning in a typical undergraduate engineering laboratory environment. Specific topics discussed in this chapter are the associated learning objectives structure of personal computer-based DAQ systems, development of simple Virtual Instruments using basic functionalities of LabVIEW, and addition of enhanced functionalities for interaction with external hardware. We also discuss the use of LabVIEW in function generation, filtering, and interaction with physical instruments such as function generators and oscilloscopes.
Cognitive Correlaretes of Physics Achievement of Some Nigeria Senior Secondary Students
Some cognitive correlates of physics achievement of some Nigeria senior secondary students were considered in the study. Specifically, the study examined the relationship between measures of student’s field independency. Cognitive tasks, formal reasoning and their achievement in physics. Purposive and stratified random sampling techniques were employed to obtain a sample of 524 senior secondary two students from six education zones in Kogi State of Nigeria. Three instruments were used. They are science Reasoning Tasks (SRTs). Group Embedded Figures Test (GEFT) and Physics Achievement Test (PAT). Data analysis using multiple regressions reveals that measures of students’ fields’ independency and cognitive tasks predicted student’s achievement in physics generally. However, only measure of field independency predicted students’ achievement in physics in the higher order cognitive demand questions. Measures of formal reasoning had no significant relationship with students’ achievements in physics generally or in higher order cognitive demand questions in physics. However, the overall relationships between measures of field independency, cognitive tasks, formal reasoning and students’ achievement in physics generally and in higher order cognitive demand questions in physics were both significant. Educational implications of these findings were discussed.