Physix keywords Flashcards
Current-Carrying Wires
When current flows through a wire, a magnetic field is generated
around it. The strength of the field depends on the magnitude of the current and the distance
from the wire.
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 opposite directions, causing
rotation.
Electromagnet
A solenoid with an iron core. The magnetism of an electromagnet can
be switched on and off, and the strength changed, through varying the current in the
solenoid.
Generator Effect
When there is relative motion between an electrical conductor and a
magnetic field, a voltage will be induced across the ends of the conductor. A current will flow
if this conductor is part of a complete circuit.
Induced Magnet
A material that becomes a magnet when it is placed in an existing
magnetic field, but loses its magnetism quickly once it is removed. Induced magnetism
always produces attractive forces.
Like Magnetic Poles
When matching poles of a magnet are brought near each other they
repel each other.
Loudspeaker
A device that converts variations in current into vibrations of a diaphragm to
produce corresponding sound waves.
Magnetic Field Lines
Lines that show the strength and direction of a magnetic field. The
lines point from North to South and their concentration represents the magnitude of the field.
Solenoid
A wire wrapped into the shape of a coil, that has a strong and uniform
magnetic field inside of it. The solenoid’s magnetic field strength can be increased by
adding an iron core.
Step-Down Transformer
A transformer that has a smaller potential difference in the
secondary coil than in the primary coil. This is a result of the secondary coil having
fewer turns.
Step-Up Transformer
A transformer that has a larger potential difference in the
secondary coil than in the primary coil. This is a result of the secondary coil having
more turns.
Transformer
An iron core with a primary and secondary coil of wire wound around
opposite ends. Transformers can change the magnitude of an alternating voltage.
Turns Ratio
The number of turns in the primary coil of a transformer over the number
of turns in the secondary coil. This is equal to the voltage ratio for a 100% efficient
transformer.
Voltage Ratio
The voltage across the primary coil of a transformer over the voltage
across the secondary coil.
