Ward's World Activity Guides

Page 2 + ward ' s science 5100 West Henrietta Road • PO Box 92912 • Rochester, New York 14692-9012 • p: 800 962-2660 • wardsci.com Find materials for this activity at wardsci.com. Discover more free activities at wardsworld.wardsci.com Step-by-Step Procedure: Indoor Lab Portion: 1. Group students or create stations throughout the room. The same experiment will be performed in each group/at each station. 2. Place a small piece of clay/playdoh onto the table top. Embed the horseshoe magnet into the clay with the open end (poles) pointing directly towards the ceiling (think football field goal look). 3. Connect the 2 ends of the wire alligator clips onto the galvanometer (or multimeter) thereby creating a circuit. Each protruding prong of the galvanometer will have just one end of the wire attached to it. 4. Find the rough middle of the wire length. Have students move the middle wire area in between the open-end poles of the horseshoe magnet. This would be an up-and-down motion by the poles (ends). 5. Students move the wire slowly at first. Move the wire up and down several times inside the horseshoe magnet ("Kids, pretend the magnet is an alligator and have the wire go in and out of its mouth several times). Read the measurements on the galvanometer/multimeter. 6. Repeat step "5" above with a medium speed and a fast speed. Record the measurements on the galvanometer/multimeter each time. (3 trials can be done for slow/medium/fast and an average calculated for all 3 speeds. 7. Ensure the wires are connected as motion may loosen the alligator clips/connections to the galvanometer/multimeter. Outdoor Demonstration: 8. Now, use the invisible magnetic field lines that emanate from the magnetic north and south poles of the Earth! The Earth itself will be our magnet. The extension cord will be our moving wire! 9. Take one galvanometer/multimeter, 2 alligator clips, and the 75'–100' extension cord (two cords maybe connected and taped together to obtain this optimal length). 10. Attach the alligator clip at the end of one wire to the ground prong of the extension cord (the "third" prong). Attach this wire's other end to the galvanometer. 11. Take the second wire, and keeping its alligator clip closed, push the clip into the ground receptacle on the other end of the extension cord. Attach the other end of this second wire to the other contact on the galvanometer/multimeter. 12. Align the extension cord in an east-west direction as moving the rope through the Earth's north-south magnetic field lines this way will guarantee the most time spent moving along the magnetic field lines 13. Leave both ends of the extension cord on the ground. It helps to have two students stand on the cords near the ends to make sure the galvanometer/multimeter stays connected to the cord. 14. Have two additional students pick up the middle half of the cord and twirl it like a jump rope. It can rotate either clockwise or counterclockwise. Have the students observe the galvanometer/multimeter and record their observations on the worksheet. Electric current will show as the "jump rope" extension cord will pass through the unseen magnetic field (lines) from the Earth's magnetic North Pole (North America)! 15. Record the data. Consider taking an average of 3 tries with the "jump rope" at 3 different speeds (as more students will get to participate!). 16. Data may be graphed for both "inside" and "outside" average currents. Class averages may be compiled as well as whole-grade averages graphed! Expected Results: Student will see that the faster the wire is moved both for the inside and outside demonstration, the more the electric current increases on average as indicated by the galvanometer/ multimeter. Teaching Notes: • Student engagement will be high especially for the outside demo. • Consider (consider) allowing students to jump rope the extension cords! Electromagnetic Induction Lab: Creating Electric Current from a Magnetic Field (continued)

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