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Physics library

Course: Physics library > Unit 18

Lesson 7: Electric motor

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Spinning compass

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By pulsing the connection to the battery we can cause a compass to spin. How is this working? Created by Brit Cruise.

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Patrick Rivera
Posted 10 years ago. Direct link to Patrick Rivera's post “Is there some benefit to ...”
Is there some benefit to the salt to the reaction and does it need it be used for this to work?
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(3 votes)
Answer
- brit cruise
  Posted 10 years ago. Direct link to brit cruise's post “Great question. Check out...”
  Great question. Check out this video:
  https://www.youtube.com/watch?feature=player_embedded&v=6U9f8Q3Y_SY
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  (3 votes)
Kreday2014
Posted 10 years ago. Direct link to Kreday2014's post “what is this trying to sh...”
what is this trying to show me
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(2 votes)
Answer
- brit cruise
  Posted 10 years ago. Direct link to brit cruise's post “This simple demo is the b...”
  This simple demo is the basis for the electric motor....Can you think of why this is? Is it possible to make something to spin without using your hands?
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  (2 votes)
я̿€̿ρ̿Ł̿ɪ̿т̿Ǻ̿ƶ̿
Posted 9 years ago. Direct link to я̿€̿ρ̿Ł̿ɪ̿т̿Ǻ̿ƶ̿'s post “so does the polls have an...”
so does the polls have anything to do with the compass here?
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(2 votes)
Answer
Jade H.
Posted 11 years ago. Direct link to Jade H.'s post “since nickels and pennies...”
since nickels and pennies are different types of metals(i'm pretty sure), how does it make the compass spin?
Button navigates to signup pageComment on Jade H.'s post “since nickels and pennies...”
(0 votes)
Answer
- Stu Dent
  Posted 10 years ago. Direct link to Stu Dent's post “all bodies have a natural...”
  all bodies have a natural magnetic field. the coils multiply/intensify this magnetic field when the electric current flows through them.
  Comment on Stu Dent's post “all bodies have a natural...”
  (4 votes)
AndrewTheKim
Posted 6 years ago. Direct link to AndrewTheKim's post “could you replace the wat...”
could you replace the water with ice? what would happen?
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(1 vote)
Answer
- Daniel Venable
  Posted 5 months ago. Direct link to Daniel Venable's post “I don't think that would ...”
  I don't think that would work. The ions need to move around freely in the water.
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  (1 vote)
Tulsi Prasad
Posted 2 years ago. Direct link to Tulsi Prasad's post “Can we replace the salt w...”
Can we replace the salt water solution with a on/off switch or push button? I want to know what the significance of salt water is in this demonstration.
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(1 vote)
Answer
danielguinness1
Posted 9 years ago. Direct link to danielguinness1's post “how much water did you us...”
how much water did you use
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(1 vote)
Answer
Elite Prøgramming
Posted 9 years ago. Direct link to Elite Prøgramming's post “would it still work witho...”
would it still work without saltwater?
just curious...
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(1 vote)
Answer
- Michael Zero
  Posted 8 years ago. Direct link to Michael Zero's post “It has to have an electro...”
  It has to have an electrolyte solution to work, so Salt Water is good. Maybe Gatorade would also?
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  (1 vote)
jc99612510
Posted 9 years ago. Direct link to jc99612510's post “how come the compass move...”
how come the compass moves faster ?
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(1 vote)
Answer
- ₦Ɇ฿ɄⱠ₳
  Posted 3 years ago. Direct link to ₦Ɇ฿ɄⱠ₳'s post “The more frequently he pu...”
  The more frequently he puts it in, the faster the compass needle will spin.
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  (1 vote)
Sebastian
Posted 9 years ago. Direct link to Sebastian's post “I get it now the salt wat...”
I get it now the salt water must be conducting a magnetic field
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(1 vote)
Answer

Video transcript

Salt water.