7 Magnetism and Electromagnetism Flashcards
What is an alternator?
A device that makes use of the generator effect to generate an alternating current.
What are current carrying wires?
When current flows through a wire, a magnetic field is generated around it. The strength of the field is dependant on the magnitude of the current and the distance from the wire.
What is a dynamo?
A device that makes use of the generator effect to generate a direct current.
What is an electric motor?
A current-carrying coil of wire in a magnetic field. The two sides of the coil that are perpendicular to the magnetic field experience forces in the opposite direction, causing rotation.
What is an electromagnet?
A solenoid with an iron core.
State the generator effect
When there is a relative motion between an electrical conductor and a magnetic field, a potential difference will be induced across the ends of the conductor. A current will flow if this conductor is part of a complete circuit.
What is an induced magnet?
A material that becomes a magnet when placed in an existing magnetic field, but loses its magnetism quickly once removed from the magnetic field. Induced magnetism always produces attractive forces.
What is a magnetic compass?
A device containing a small bar magnet that points in the direction of the earths magnetic fields.
What are magnetic field lines?
Lines that represent the strength and direction of a magnetic field. The field line direction at any point is in the direction that a force would act on another north pole if placed at that point.
What is a magnetic field?
The region around a magnet in which another magnet or magnetic material will experience a force.
Which materials are magnetic?
Iron, Steel, Cobalt and Nickel
What are magnetic poles?
The regions of a magnet where the magnetic fields are at their strongest.
What is a microphone?
A device that uses the generator effect to covert the pressure variations of sound waves into variations in the electrical current of a circuit.
What is the motor effect?
When a current-carrying wire is placed in a magnetic field, a force will be experienced between the wire and the magnet responsible for the field.
What is a permanent magnet?
A magnet that produces its own magnetic field.
