Magnetic Effects of Electric Current: The Electromagnet
Explore the **magnetic effect of electric current** by building a simulated electromagnet. Investigate how factors like **current** and the **number of turns** in the coil affect the magnet's strength.
Key Concepts: Electromagnetism
▼An electromagnet is a **temporary magnet** created when electric current flows through a wire wound around a piece of soft iron (the core). When the current is switched off, the magnetism vanishes.
- **Current:** Increasing the current flowing through the coil increases the magnetic field strength.
- **Turns:** Increasing the number of turns in the coil increases the magnetic field strength.
- **Core Material:** Using a **soft iron core** significantly concentrates and amplifies the magnetic field.
Experiment 1: Building and Testing the Electromagnet
Adjust the current and number of turns to simulate the electromagnet's ability to lift objects.
Strength Low: Cannot lift heavy objects.
Experiment 2: Electromagnet Applications Challenge
Match the device to its key operating principle/component.
Electromagnets are superior to permanent magnets in applications where control is essential. Their strength can be **varied** (by changing current/turns), and their magnetic effect can be **switched on and off instantly**.
Device Applications
Uses an **electromagnet** to repeatedly pull an armature and break the circuit, which is the perfect example of switching the magnetic field **on and off** quickly.
The crane uses a massive **electromagnet** which is switched **on** to pick up iron scrap and then **off** to drop it instantly, showcasing the control feature.
The rotating part of an electric motor uses the principle that a **current-carrying conductor placed in a magnetic field experiences a force** (a core principle of electromagnetism).
