Report 7-2

Experiment 7 - 7.1: Induced emf, 7.2: Transformers Student name: Juliana Dupuy Pre-lab section: 1) 7.1 Introduction:   Explain the theory behind this experiment in a paragraph between 75 and 150 words . (1.0 points) An electromotive force (emf) is produced when a magnet moves through a coil to a change in magnetic flux. Faraday's law, states emf = -N(Δϕ/Δt), where (Δϕ/Δt) is the flux change rate for each turn, N is the total number of wires turns. A negative sign denotes the polarity of the electromagnetic field (emf), also known as the direction of the current. The direction of current is determined by Lenz's law, which states that it opposes the cause of induction. When the magnetic flux increases, the incoming flux causes the emf to reach its highest point. The emf polarity is determined by the connections made to the voltage sensors. The software then records and displays the induced Emf vs. time after calculating the regions beneath peaks that represent flux changes. Using a voltage sensor to measure the emf created by lowering a magnet through a coil, we examined the relationship between ε = ∆T/ ∆Φ. 2) 7.1 Hypothesis:   In an If /Then statement, highlight the purpose of the experiment. (0.5 points) If the magnet's path changes when it is traveling through a coil, then the polarity of the induced EMF peaks changes with respect to direction. .  3) 7.2 Introduction:   Explain the theory behind this experiment in a paragraph between 75 and 150 words . (1.0 points) In this experiment, we went over transformers devices that transfer energy between circuits via electromagnetic induction. They convert AC input to output levels and serve as trustworthy voltage converters. Transformers work by encircling a high permeability core with two electrically isolated coils to improve the inductance to capacity. According to Faraday's law, the primary coil generates alternating flux whenever an alternating current source engages it. Both coils produce emf because of this. Connected electronics are powered by an alternating current produced by the secondary coil's emf. Emf is correlated with number of turns (N) and the rate of change of magnetic flux (∆Φ/∆t), expressed as ε = ∆Φ/∆t. In a perfect transformer, the turn ratios (εs/εp = Ns/Np) and the Emf ratios coincide. By differentiating step-up and step-down transformers according to the turns of the coils, this illustrates the adaptability of transformers in adjusting alternating current voltages. 4) 7.2 Hypothesis:   In an If /Then statement, highlight the purpose of the experiment . (0.5 points) If the number of turns in the main coil is greater than the number of turns in the secondary coil, then the induced emf in the second coil will be smaller than the emf in the first coil. Post-lab section: 5) 7.1 Discussion: In a paragraph between 100 and 150 words , explain what you learned from the results obtained in the experiment . What conclusion can you draw from the results of this lab assignment?   (1.0 points) The results of this experiment showed that when the magnet was dropped with its North pole facing down, the outgoing peak was larger; however, when the South pole faced

down, the opposite was observed. As the magnet descends faster, the induced electromagnetic field intensifies as it passes through the solenoid. This results in a greater EMF due to the increased velocity that produces a smaller shift in time. The EMF is much lower as it enters the coil in addition to the magnet's slower starting velocity. Therefore, it can be concluded that the magnet's position significantly affects the quantity of EMF produced, with the largest levels occurring during the experiment while the North pole is pointed downhill. The result demonstrates a clear relationship between the orientation of the magnet and its future electromagnetic characteristics. 6) 7.1 Conclusion: In one   sentence,   compare the results of the experiment with your Hypothesis. Why? (0.5 point) An associated shift in the polarity of the induced EMF peaks when the magnet's direction changes through the coil, supports my hypothesis that the magnet's orientation directly influences the strength and direction of the induced EMF. 7) 7.2 Discussion: In a paragraph between 100 and 150 words , explain what you learned from the results obtained in the experiment . What conclusion can you draw from the results of this lab assignment?   (1.0 points) The results of this experiment made it very clear what a transformer would do as expected. When the number of turns in the main coil rose relative to the number of turns in the secondary coil, the induced emf in the secondary coil dropped. This validated the theory and showed how well the transformer could convert step-up voltage. The emf in the secondary coil was greater than that of the primary coil when the number of turns in the secondary coil was greater than that of the main coil. This demonstrated that step- down voltage conversion is possible. These results emphasize the significance of turn ratios for influencing a transformer's voltage transformation. 8) 7.2 Conclusion: In one   sentence,   compare the results of the experiment with your Hypothesis. Why? (0.5 point) The experiment's results confirm my hypothesis because they showed that the number of turns in the main coil was increased in relation to the secondary coil, resulting in a lower induced emf in the secondary coil than the emf in the primary coil. 9) 7.1 Data Analysis: Attach an image of the data and instruction pages containing tables with final calculated values, figures, plots, charts and responses to questions or specified calculations here. (5 points) This should include: Table 1 Measurement Vin (V) Vout (V) #1: 1mNd -3.288 2.033 #2: 1msd -1.828 3.174 #3: 2mNd -3.944 2.576 #4: 2mSd -2.74 4.119 Table 2

Question 5:  0.2 points Question 6:  0.2 points

Question 4: 0.25 points Question 5: (a): 0.25, (b): 0.2 (c): 0.20