W= Lab 9 Measuring the Earth magnetic field ? No Label Q se References gs Review View Aav EVEVEY AaBbCcDdEe AaBbCcDdEe AaBbC AaBbCc[ Av DV Av Normal No Spacing Heading ? Heading 2 Styles Dictate Pane EARTH MAGNETIC FIELD Name This lab uses your phone and the App Phyphox or another App to measure the magnetic field of the Earth. If you do not have a smartphone, please contact your instructor to complete an alternative lab activity . Introduction If you want to go more in-depth about the earth's magnetic field, you may read interesting facts | on the NOAA website here: https:/oaa.maps.arcgis.com/apps/MapJournal/index.html?appid=369045c4d1aa408694d3759 d1aa5ede4 The Earth is surrounded by a magnetic field due to a dynamo effect at its interior. The field is similar to the field originated by a bar magnet, which has the magnetic south pole close to the geographic north pole and the magnetic north close to the geographic south pole. Currently, the axis of the magnet is offset by about 11 degrees with respect to the earth rotational axis. Magnetic field is represented by field lines (in blue in the picture). As one may see in Fig. 1, in the northern hemisphere, the magnetic field lines are pointing toward the center of the Earth while in the southern hemisphere they are pointing away from the center of the Earth. At a given location, the inclination angle is the angle between the magnetic field vector and the horizontal plane (the plane tangent to the surface of the Earth at that point). The inclination is positive when the magnetic field points downward into the Earth and negative when it points upward. See Fig.2 below. Spin axis Spin The geographic North Pole is a axis magnetic south pole. Magnetic field lines Figure 1. The Earth magnetic field (Hyperphysics.com ) Focus E hited States) Ex Accessibility: Investigate MacBook Air gn... w- Lab 9 Measuring the Earth magnetic field ? No Label References Mailings Review View A Aav Ap EVEvav AaBbCcDdEe AaBbCcDdEe AaBbC AaBbCCC ADVA E Normal No Spacing Heading 1 Heading 2 Styles Pane Plane tangent to the Earth surface Inclination & Bz North Figure 2. The B vector and the Inclination angle 9 (theta) Activity 1. On your phone, download the free App. Phynhox or any other app that would use your phone magnetometer and give you the three coordinates of the B- field at your location. wa phyphox physical phone experiments B. Bo Image from Physhex Focus ited States) Ex Accessibility: Investigate MacBook Air DII DD F10 Q F9 20 F7 F8 5 F6 F4 F3W. Lab 9 Measuring the Earth magnetic field @ No Label erences Mailings Review View EFE AaBbCcDdEe AaBbCcDdEe AaBbC AaBbCc[ A Normal No Spacing Heading 1 Heading 2 Style Pane Image from Phxshox 2. On the NOAA website check what the total magnetic field and inclination is at your location. For a detailed description on how to do it, please refer to this video associated with this lab 3. The table will look like this one: Magnetic Field Model Used: WMM-2020 atitude : 390 1' 43" N Longitude 779 23' 30" W Elevation; 0.0 km Mean Seadevri Date Declination Inclination Horizontal North Comp East Comp ( + E I - W ) ( + D 1 : U ] Vertical Comp Total Field Intensity ( + N 1 - 5 ) ( + El - W ( + D I - U) 2020-08-31 -10 34' 28" 650 29' 25" 21,169.3 nT 20, 809.8 nT -3,884.8 nT 46,431.3 nT 51,029.4 nT Change/year 0 0' 9/yr 42.6 nT/yr 42.1 nT/yr 6.9 nT/yr -133.7 nT/yr Uncertainty 0 0 22 ' 0 13' 128 nT 131 nT 94 nT 157 nT 145 nT 4. Include here a picture of the NOAA magnetic field at your location. You may want just to include the B field values and take out your location latitude and longitude. (0.5 Rt) [Screenshot] 5. For a detailed description on how to start to run the data collection on the smartphone, please watch this video called Earth magnetic field associated with this lab. 6. Run the measurement with your phone and see if the data for the total B is close to the expected value of the total field. If it is not close in value, then rotate the phone in all directions, making an 8 path with the phone. After this "calibration" most probably you will be able to have the correct value. 7. Place the phone on a flat surface away from any magnetic source (laptops, wires, magnets, etc). Run the App. Rotate the phone until the x component of the B field is zero. In this way your By is along the geographical North direction. Now, your phone is like a compass! ates) TX Accessibility: Investigate Focus MacBook Air. . W Lab 9 Measuring the Earth magnetic field No Label Q References Mailings Review View Aav Po AaBbCcDdEe AaBbCcDdEe AaBbC AaBbCc[ 0 Normal No Spacing Heading 1 Heading 2 Styles Dictat Pane 8. Record the Bx, By, the Bz, and the B total in Table 1. 9. The SI unit of the B field (Magnetic field) is called Tesla T. The B field is measured in nano-Tesla (1 nT. =1 x 10 T) on the NOAA website. In the App the units used are micro-Tesla and 1 micro-Tesla is equal to 1x 10 'T. If you are in the USA, on average on the App you expect to see around 50 micro Tesla for the B total. 10. Using trigonometry, plus the values of Bz, and By determine the inclination angle. The formula you want to use is the following: B z component Inclination angle = inverse tangent By component 9 = tan-1(B z component By component 11. On Table 1, record the inclination angle, 9. 12. Repeat the measurements five more times and report the data on Table 1. 13. Add here screenshots of your phone with the B-field data. Five total screen shots. (0.5 each, total 2.5 points) [Screenshots] 14. Find the average quantities for the inclination angle and the B total. (3pts) Average of the B total and units Average of the inclination angle, Theta_ Focus States) My Accessibility: Investigate MacBook AirW Lab 9 Measuring the Earth magnetic field @ No Label ~ es Mailings Review View V 2 - V AaBbCcDdEe AaBbCcDdEe AaBbC AaBbCc[ IV Normal No Spacing Heading 1 Heading 2 Table 1 (14pts) Bx (It should By BZ B total Theta be about zero value) Accessibility: Investigate Focus