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Course: Physics library > Unit 18
Lesson 5: Discovery of electromagnetismElectromagnetic field (above vs. below)
Testing the direction of force when the current carrying wire is above vs. below a compass. What does this tell us? Created by Brit Cruise.
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- Does anyone know if there's a video about Lorentz force? I couldn't find one in the electromagnetism section.(7 votes)
- i don't think so but you can look at the top where it says search subjects, skills and videos.(1 vote)
- how strong magnetic field can an electromagnet produce when given a power of 1 watt?
also how big/small object can it attract??(4 votes) - I believe that the science discovery kahn videos should have more voices or how to's to engage the learner to pay more attention. Does anyone agree?(3 votes)
- I think it's supposed to be a DIY experiment intro.(1 vote)
- If the wire has an insulator plastic around it, how does the field pass through the thick coating then?(1 vote)
- Why do you need that roll of black tape?(1 vote)
- The tape serves no purpose in the experiment besides holding the compass in the air, so the field and the direction of force can be observed in a three-dimensional manner, both above and below the compass.(4 votes)
- Does it matter the order that you connect the wires to the battery terminals?(2 votes)
- Actually, that does matter. As you can see in the next video, the compass will rotate the other way.
https://www.khanacademy.org/science/discoveries-projects/discoveries/Electromagnet/v/electromagnetic-field--forward-vs--reverse(1 vote)
- should there be a large current flowing through the wire for compass to show deflection(2 votes)
- That's really interesting. Why does it do that, though? I've been thinking and I haven't come up with anything.(1 vote)
- Primarily due to the magnetic field s or more commonly known as poles
correct me if i am wrong i am only in the 8th grade(2 votes)
- please explain how did the direction of rotation of magnetic needle changed ?(1 vote)
Video transcript
clockwise counterclockwise