4-5.10 Summarize the factors that affect the strength of an electromagnet.
Electromagnets & Magnet Strengths
Essential Question: What are the properties of electromagnets and what affects magnets strength?
Electromagnets
An electromagnet is a magnet that is made using electric current. An electromagnet is magnetic, or acts like a magnet, only when the electric current is flowing. This means that electromagnets can be turned on and off. Electromagnets are part of the equipment that starts a car. They are also part of televisions and computers.
The electromagnet has a coil of wire wrapped around an iron core. The core might be an iron bolt or nail. The wire is connected to a source of electricity. When electric current flows, it produces a magnetic field around the core. The diagram shows a simple electromagnet.
An electromagnet has the same properties as a magnet. They both attract objects that contain nickel, iron, or cobalt. They both have poles. For both, unlike poles attract and like poles repel.
The Strength of Magnets
The pull of all magnets is strongest around the poles. But some magnets are much stronger than others. You can test the strength of a magnet or electromagnet by counting the number of objects, such as paper clips, that it can pick up.
You can make an electromagnet stronger by changing different parts of it. You can wrap the wire around more times. You can change the core. An iron core produces the strongest magnet. A thicker core also makes a stronger magnet. You can also increase the electricity flowing through the wire. One way to do this is to add more batteries to the circuit.
Essential Question: What are the properties of electromagnets and what affects magnets strength?
Electromagnets
An electromagnet is a magnet that is made using electric current. An electromagnet is magnetic, or acts like a magnet, only when the electric current is flowing. This means that electromagnets can be turned on and off. Electromagnets are part of the equipment that starts a car. They are also part of televisions and computers.
The electromagnet has a coil of wire wrapped around an iron core. The core might be an iron bolt or nail. The wire is connected to a source of electricity. When electric current flows, it produces a magnetic field around the core. The diagram shows a simple electromagnet.
An electromagnet has the same properties as a magnet. They both attract objects that contain nickel, iron, or cobalt. They both have poles. For both, unlike poles attract and like poles repel.
The Strength of Magnets
The pull of all magnets is strongest around the poles. But some magnets are much stronger than others. You can test the strength of a magnet or electromagnet by counting the number of objects, such as paper clips, that it can pick up.
You can make an electromagnet stronger by changing different parts of it. You can wrap the wire around more times. You can change the core. An iron core produces the strongest magnet. A thicker core also makes a stronger magnet. You can also increase the electricity flowing through the wire. One way to do this is to add more batteries to the circuit.
Learning Task #1:
Use Streamline Video Clip: Electromagnets to introduce students to the components of an electromagnet, as well as the ways to make an electromagnet stronger. Learning Task #2: In groups, students will create a Venn Diagram, listing components of “Strong” and “Weak” electromagnets, and including common components of ALL electromagnets in the center. Learning Task #3: Write Like a Scientist: Properties of Magnets and Electromagnets |
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