Paper 2 Magnetism & Electromagnetism Flashcards
What are permanent magnets?
Permanent magnets
PRODUCE THEIR OWN MAGNETIC FIELD
What are Induced Magnets?
Induced magnets
BECOME a magnet when placed in a MAGNETIC FIELD
When removed from the magnetic field, they LOSE THEIR MAGNETISM quickly
What do like pole do?
Like poles - REPEL
(The north pole of a magnet will REPEL (push away) a north pole
A south pole will REPEL another south pole)
UNLIKE POLES …..
Unlike Poles … ATTRACT
The north pole of a magnet will attract the south pole of another magnet
What does it mean when the FIELD LINES around a magnet are drawn CLOSED TOGETHER?
Field lines show closed together mean … that the strength of a magnet is STRONG
There are 2 types of magnetic poles
Magnetic poles -
NORTH seeking & SOUTH seeking poles
What is a magnetic field?
Magnetic Field is:
the REGION around a magnet where force acts on another magnet/magnetic material
Name magnetic materials:
Magnetic materials
. Magnets . Iron . Steel . Nickel . Cobalt
Where is the magnetic field strongest?
The Magnetic Field is strongest at: THE POLES
What is the FLUX DENSITY?
The Flux Density is:
. The density (THE THICKNESS) of the magnetic field lines
. It indicates the STRENGTH of the FIELD
. The CLOSER the lines - the HIGHER the flux density - the SRONGER the field & the GREATER force that would be felt by another magnet
Field lines run in which direction?
The field lines run from NORTH to SOUTH
The strength of a magnetic field depends on:
The strength of a magnetic field depends on:
. the SIZE of the CURRENT & the DISTANCE from the WIRE
What is a SOLENOID?
A Solenoid is when:
. a WIRE is LOOPED into a CYLINDRICAL COIL
. the LOOP INCREASES the strength of the MAGNETIC FIELD
. AN IRON CORE can be added to create a STRONGER FIELD … this is called an ELECTROMAGNET
Why does a SOLENOID increase the magnetic field:
The SOLENOID increases the magnetic field because:
. It concentrated a LONGER piece of WIRE into a smaller area
. the LOOPED shape means that the magnetic field lines are ALL in the SAME DIRECTION
. strong UNIFORM field inside the SOLENOID
How can the north pole of a SOLENOID be found?
The north pole of a SOLENOID can be found by:
. THE RIGHT HAND GRIP METHOD
An example of an ELECTROMAGNETIC DEVICE
An Electromagnetic device -
Electric Bell …
. Push the switch - the ELECTROMAGNET is MAGNETISED
What does the Force (N) depend on:
The FORCE depends on:
. Magnetic Flux DENSITY (T)
. Current (A)
. Length (m)
The force (A) equals
Force (N) = B x I x l
force = magnetic flux density (T) current (A) length (m)
When would you use FLEMING’s LEFT HAND RULE?
FLEMING’S LEFT hand rule is used to find:
the FORCE on the conductor
Thumb = Movement (direction of force)
First finger = Field (magnetic field)
Second = Current (direction of current)
What do we use the motor effect for?
The motor effect is used:
In MOTORS to CONVERT ELECTRICAL ENERGY into KINETIC ENERGY
What happens if the conductor is parallel to the the magnetic field?
If the conductor is parallel to the magnetic field it will NOT EXPERIENCE A FORCE
Advantages of an ELECTROMAGNET?
An Electromagnet can:
. Be switches on and off - so it can pick up a car then release it.
. A permanent magnetic cannot be switches on and off
Electromagnetic radiation wave lengths:
Radio waves 1500 m
Visible light 5 x 10 -7m
Ultraviolet wave 3 x 10- 8m
X-rays - 1 x 10 -11m
