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How can the strength of an electromagnet be varied?
The strength of an electromagnet can be increased by increasing the number of loops of wire around the iron core and by increasing the current or voltage. You can make a temporary magnet by stroking a piece of iron or steel (such as a needle) along a permanent magnet.
What type of magnet would you use to move around old cars at a junkyard?
Electromagnets
- A soft iron core is useful when you want an electromagnet to switch off rapidly.
- Some cranes use electromagnets to pick up scrap cars. They can let go of the car by turning off the current.
- Electric bells use electromagnets.
- Electrically operated switches called relays also use electromagnets.
How are scrap magnets made?
In a scrapyard, a crane has a large iron disc that is not a permanent magnet. The crane operator lowers the electromagnet into a pile of scrap steel and then switches on the electricity Scrap steel is attracted to the disc.
Can you make a magnet stronger?
If you can find a very strong magnet, repeatedly rub it across your weakened magnet. The strong magnet will realign the magnetic domains inside the weakened magnet [source: Luminaltech]. Magnet stacking One way to make weak magnets stronger is by stacking more of them together.
Which of the following is the correct way of moving a magnet along a magnetic material to turn it into a temporary magnet?
You can make a temporary magnet by stroking a piece of iron or steel (such as a needle) along a permanent magnet. There is another way that uses electricity to make a temporary magnet, called an electromagnet.
What are junkyard magnets made of?
Mechanically, an electromagnet is pretty simple. It consists of a length of conductive wire, usually copper, wrapped around a piece of metal. Like Frankenstein’s monster, this seems like little more than a loose collection of parts until electricity comes into the picture.