Electromagents Flashcards
So how are magnetism and electricity connected?
Flowing electrons produce a magnetic field, and spinning magnets cause an electric current to flow.
The region around a magnet where magnetic effects can be experienced is called the
magnetic field.
Faraday’s Three Rules for Magnetic Field Lines
Each magnetic field line is a continuous loop that leaves the north end of the magnet, enters at the south end and passes through the magnet back to the north end.
Field lines do not intersect.
The closeness of the magnetic field lines represents the strength of the magnetic field.
What is a solenoid?
A solenoid is a tightly wound coil of wire (usually copper) that acts as a magnet when carrying electric current.
What happens if you place a core (usually a piece of iron) in the middle of a solenoid?
If we place a core (usually a piece of iron) in the middle of the solenoid, then we can increase the magnetic field and produce an electromagnet
What is an electromagnet?
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. The magnetic field dissapears when the current is turned off. Electromagnets usally consist of wire wound into a coil.
Q
What is a permanent magnet?
A permanent magnet is an object made from material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door.
How do magnets generate electricity?
When a magnet is moved inside a coil of wire, it causes the electrons in the atoms inside the wire to move.
The moving electrons in the wire create an electric current!
This current is alternating current (AC) as it changes direction
What is a simple electric motor?
These work opposite to a generator.
When the current flows through the coil of wire, it interacts with the magnetic field and the coil spins.
What does the magnet’s speed in and out of the solenoid have on the current?
It affects the current being generated. The faster the magnet moves in and out of the solenoid, the greater the current on the ammeter.
Does any current flow when the magnet is still within the solenoid?
When the magnet is still in the solenoid, no current was generated on the ammeter.
Does changing the Pole (north or south) that approaches the solenoid to have an effect?
Yes. It changes the directions of the current.
Can you suggest what you could change to induce more current?
- Increase the number of turns of wire in the coil. The more coils the more current induced.
- The faster you move the magnet in and out of the solenoid the greater the current.
- Increasing the strength of the magnetic field. With a stronger magnetic field, a bigger current is induced due to more lines of force to cut.
How have advances in knowledge of the electromagnetic spectrum impacted our society?
Increase the number of turns of wire in the coil. The more coils the more current induced.
2. The faster you move the magnet in and out of the solenoid the greater the current.
3. Increasing the strength of the magnetic field. With a stronger magnetic field, a bigger current is induced due to more lines of force to cut.
What are magnets used for?
Magnets are used in the generation of electricity and the operation of motors.
