Magnets and Electricity
Grade 3 · Science · Study Guide
Explore how magnets attract and repel objects and how electricity flows through circuits to power our world.
A magnet is an object that creates a magnetic force that can attract or repel certain materials. Magnets attract objects made of iron, nickel, and cobalt. Wood, plastic, rubber, and glass are not attracted to magnets. Every magnet has two poles: a north pole and a south pole. Opposite poles attract each other, while like poles repel or push each other away.
The area around a magnet where its force can be felt is called the magnetic field. Earth itself is like a giant magnet with a magnetic north and south pole, which is why compass needles always point north.
Electricity is the flow of tiny particles called electrons through a material. Materials that allow electricity to flow through them easily are called conductors. Metals like copper and aluminum are good conductors. Materials that block electricity are called insulators. Rubber, plastic, and wood are insulators.
For electricity to flow and power a light bulb or motor, it needs a complete path called a circuit. A simple circuit includes a battery (which provides energy), wires to carry the current, and a device like a bulb. If the circuit is broken — for example, by a switch — electricity stops flowing and the bulb goes out. A switch is used to open and close a circuit to control the flow of electricity.
Magnets and electricity are connected: a moving magnet near a coil of wire can generate electricity, which is how power plants make the electricity we use at home.
Key terms
- Magnet
- An object that produces a magnetic force that attracts iron, nickel, and cobalt.
- Magnetic poles
- The two ends of a magnet (north and south) where the magnetic force is strongest; opposite poles attract, like poles repel.
- Circuit
- A complete, closed path through which electricity can flow.
- Conductor
- A material that allows electricity to flow through it easily, such as copper wire.
- Insulator
- A material that does not allow electricity to flow through it, such as rubber or plastic.
- Switch
- A device that opens or closes a circuit to start or stop the flow of electricity.
Flashcards
- Magnet
- An object that attracts iron, nickel, and cobalt using magnetic force.
- North pole
- One of the two ends of a magnet; attracts the south pole of another magnet.
- South pole
- One of the two ends of a magnet; attracts the north pole of another magnet.
- Repel
- To push away; like poles of two magnets push each other away.
- Attract
- To pull toward; opposite magnetic poles pull toward each other.
- Circuit
- A closed loop through which electricity flows.
- Conductor
- A material like copper that lets electricity flow through it easily.
- Insulator
- A material like rubber or plastic that blocks electricity from flowing.
Questions
Which material would be attracted to a magnet?
- Plastic ruler
- Wooden pencil
- Iron nail
- Glass cup
Show answer
Answer: Iron nail
Magnets attract metals that contain iron, nickel, or cobalt. An iron nail is attracted to magnets, while plastic, wood, and glass are not.
If you put the north pole of one magnet near the north pole of another magnet, they will attract each other.
Show answer
Answer: False
Like poles (north-north or south-south) repel each other. Only opposite poles (north-south) attract.
A complete path that allows electricity to flow is called a ______.
Show answer
Answer: circuit
A circuit is a complete, closed path that electricity flows through to power devices.
Why is copper wire used in electrical wiring?
- It is the cheapest metal
- It is a good insulator
- It is a good conductor of electricity
- It is attracted to magnets
Show answer
Answer: It is a good conductor of electricity
Copper is an excellent conductor of electricity, meaning electrons can flow through it very easily. That is why it is used in most electrical wiring.
When a switch in a circuit is open (turned off), electricity can still flow through the circuit.
Show answer
Answer: False
An open switch breaks the circuit, stopping the flow of electricity. Electricity can only flow through a complete, closed circuit.
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