FARADAY'S LAW This lab will be graded using scientific ability rubrics. To help you know what we expect, the rubrics have been included along with the instructions. Equipment available Roll of wires and wire cutter . . IOLak Bar magnet . Scotch-tape Theory Review. We will investigate how the magnetic flux can induce an electric current (or emf) in a loop of wire The magnetic flux is defined the same way as the electric flux was Im B . da ** Before you start, calibrate the IOLab accelerometer/gyroscope/magnetometer far from any computer device. Review how here https://www.youtube.com/watch?v=tfT634FMHVE&list=PL- 40XKoYvmdkd5WSRifGIU30uH3eOpdIS&index=5 For this whole lab you will use the 6ft hookup wire in your E&M PASCOS box and you will wrap it around your iOLab remote. The ends of the wire should be inserted into the G+, G- input. This is a high-gain multiplier which amplifies the signal in the wire. If it is too difficult to insert the wires into the pins, you can use the resistors to wrap the + 9070!' ends of the wires around them. Use the scotch tape to keep the loops in place. See image. - 1 .PART 1 OBSERVING EXPERIMENT: INDUCED EMF 1. Design an experiment using only a bar magnet and the IOLab to investigate what happens to the emf in a loop of wire in which you change the magnetic flux. Can you determine the direction of currents induced? Scientific Ability Inadequate Needs improvement Adequate [s able to design a The experiment may not Some important aspects of the The experiment reliable experiment yield any interesting phenomenon will not be might yield that investigates the patterns. observable. interesting patterns phenomenon relevant to the investigation of the nhenomenon. 2. Perform your experiment and record some data. Take a screenshot that shows clearly the important features and include it with this report. Scientific Ability Inadequate Needs improvement Adequate ls able to record and Some or all data are absent All relevant data is present, All relevant data are represent data in a or incomprehensible. They but recorded in a way that present, organized, and meaningful way are not organized in tables requires some effort to recorded clearly. The tables or the tables are not labeled comprehend. The tables are are labeled and placed in a properly labeled but labels are logical order. confusing. 3. Describe what is observed. Do you notice any pattern? (look particularly for direction of current and emf) Scientific Ability Inadequate Needs improvement Adequate l5 able to identifya pattern The pattern described is The pattern has minor errors or The patterns represents in the data irrelevant or inconsistent omissions. Terms proportional the relevant trend in with the data are used without clarity is the the data. When proportionality linear, quadratic, possible, the trend is etc. described in words. 4. What are the shortcomings ofthis experiment? Particularly ifyou would be interested in determining more quantitatively the relationship between changing magnetic flux and induced emf. Scientific Ability Inadequate Needs improvement Adequate ls able to identify the The shortcomings are Not all aspects of the design are All major shortcomings in an described vaguely and considered in terms of shortcomings of the experimental and no suggestions for shortcomings or experiment are suggest improvements improvements are made. improvements. identied and reasonable suggestions for improvement are made. PART 2- TESTING EXPERIMENT: A TORSIONAL OSCILLATOR 5. Based on the observing experiment you just did. Make a hypothesis for what happens (in general) inside a current loop when the magnetic flux changes Scientific Ability Inadequate Needs improvement Adequate ls able to identify the An attempt is made to The hypothesis to be tested is The hypothesis is clearly hypothesis to be tested identify the hypothesis to described but there are minor stated. be tested but is described omissions or vague details. in a confusing manner. 6. Now imagine the following experiment (DO NOT DO IT YET). Keep the wire wrapping the IOLab with ends connected to the highrgain sensor (not shown \"Wham\" in the figure to the left). a. Attach the spring to the IOLab force sensor and create a torsional oscillator by twisting the spring. 2 b. After you release the IOLab, it will spin around mt; the y axis. 2' c. Using the gyroscope you can measure the nav moving no romue angular velocity at which the IOLab is spinning F while the Highgain record the emfinduced. ' Given your hypothesis make a qualitative prediction of what F : T: x F '2'? 1? should be observed on the highgain amplifier while the IOLab spins. Be as precise as you can. Scientific Ability Inadequate Needs improvement Adequate ls able to make a A prediction is made that is A prediction is made that follows A prediction is made reasonable prediction distinct from the from the hypothesis but does not that follows from the based on a hypothesis hypothesis but is not based incorporate assumptions hypothesis and on it. incorporates assumptions. 7. Perform your experiment and sketch the observed graph (for all relevant sensors) below. Include a screenshot of your data on the iOLab for the HighrGain sensor. Scientific Ability Inadequate Needs improvement Adequate A graph is present but the The graph is present and axes are The graph has correctly axes are not labeled. There labeled but the axes do not labeled axes, is no scale on the axes.. correspond to the independent independent variable is and dependent variable or the along the horizontal scale is not accurate. axis and the scale is accurate. 8. Is the outcome of the experiment in agreement with your prediction? Are you certain that your prediction was correct given your hypothesis? Scientific Ability Inadequate Needs improvement l Adequate ls able to decide whether A decision about the A reasonable decision about A reasonable decision the prediction and the agreement/disagreement the agreement/disagreement about the outcome agree/disagree is made but is not is made but experimental agreement/disagreement consistent with the uncertainty is not taken into is made and outcome of the account. experimental uncertainty experiment. is taken into account