Global Journal of Science Frontier Research, A: Physics and Space Science, Volume 22 Issue 1

Table 8: Identification of possible systematic errors with their respective correction methods Incorrect calibration Regular calibration with an exact measurement standard. The field of view of the infrared thermometer Fix the thermometer in a position that is is larger than the screw head, where all oriented exactly towards the screw head. temperatures were taken. Consequently, the readings may include other sources of heat. Delay error, which refers to the time it takes for Take measurements until instrument reading is certain instruments to reach their equilibrium stable state, as in the case of the thermometer. Positioning of the electromagnet. Hold the electromagnet steady with a laboratory clamp From the graphs obtained in section 4.2, it can be seen that the regression coefficients between them vary very slightly, with graph 7 being higher than graph 5 by just one-thousandth more, therefore, the comparison of this indicator alone does not allow us to definitively find the model that best suits the observed data. Therefore, it was necessary to review the tools for the examination of linear models presented in Table 5. First, contrasting the adjusted R-squared of each of the graphs is more correct than comparing R-squared because the latter increases automatically with the inclusion of more variables, even if they are insignificant. In addition to this, a larger adjusted R squared implies a smaller deviation between the model and the data. For this reason, figure 8, which corresponds to the graph of voltage versus temperature, has the best value of this coefficient. The probability of the F-statistic, on the other hand, is low enough in 8, 9 and 10 to reach the conclusion that the null hypothesis does not apply. Now, the figure with the lowest F-statistic is that of the graph of voltage against the logarithm of the temperature, although all the values of this probability are of the same order of magnitude. Furthermore, all three graphs exhibit a P-value of zero, which is a good indication that there is indeed a correlation between the dependent and independent variables. Likewise, the ideal T-value is as large as possible and in this case the T-values of the coefficient and the constant of the equation for graph 8 are greater than the others. Based on the previous analysis, it can be concluded that the equation that most closely matches the data collected is that of graph 8, whose equation is V = 0.03T - 6.992. According to equation (8) for the force produced by the magnetic field of an electromagnet, the retaining force of an electromagnet is proportional to the area of the magnetized surface and to the square of the product of the current and the number of turns, called magnetomotive force, and inversely proportional to the square of the gap between the core and the winding, g. In this sense, it can be confirmed that the experimental results fit with the theory. According to the data collected, with an increase in temperature a lower attractive force is noted due to the fact that the magnetic flux decreases with the drop in current through the electromagnet, caused in turn by an increase in resistance. Additionally, as the cross-sectional area of the electromagnets used in the pre-experiment was increased, a greater force of attraction could be perceived between them and the nut. Despite having consistent and robust results, further investigation is required to accurately and precisely quantify the rate of change in retaining force versus change in coil temperature. Relationship between Temperature and the Holding Force of an Electromagnet in a Changing Magnetic Field 1 Year 2022 25 © 2022 Global Journals Global Journal of Science Frontier Research Volume XXII Issue ersion I VI ( A ) Systematic error Correction method