Electromagneti
c Effects
Putih Asmara M.Sc
Yosua Yeremia
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Table of contents
01
02
Magnetic
Fields
Electric
Motor
03
Magnetic
Forces
04
Generating
Electricity
01
Magnetic Fields
Two Types of Magnets
Permanent Magnets
Are objects that always have a
magnetic field around them all
the time. The strength and
direction of the field do not
change easily.
Non-Permanent Magnets
Are objects that temporarily
have a magnetic field around
them. The strength and
direction can be changed or
removed easily.
Magnetic vs Non-Magnetic
Magnetic
Objects are objects that
Non-magnetic Objects are objects
Objects
can be attracted by magnets.
They can also be transformed
into magnets with different
permanence
Example: iron, steel, cobalt,
nickel
that is not attracted to magnets.
They cannot be transformed into
magnets, even temporarily
Example: plastic, paper, rubber,
sciencephoto.com
Why Magnetic and Why Not?
● Not all metals are magnetic, but all magnetic materials made of
metals.
● Magnetic situations is an effect of electrons and electrostatic forces
● When you have lots of electrons that are easily moved and lined
up, your object is magnetic. And, if it can retain the lined up
position for a long time, it is a permanent magnet.
(https://sciencing.com/material-magnetic-6706107.html)
electronics-tutorials.ws
Magnet Poles
● Since electrons are lined up and concentrated
at some points, so do the magnetic strength
of a permanent magnet
● The strongest points are called poles,
categorized into North Pole and Southt Poles
● Like electrostatic forces, same poles repels
and different forces attract
● That is why earthly polarity and compass /
geographical polarity is inverted
Sun, Earth, and Compass
● Earth is magnetic since the core is made up of
molten iron. The iron electrons is lined up due
to earth rotation.
● The sun has similar phenomenon, but it
consists of plasma - a highly energized matter
that eases electron polarization even further.
● The magnetic poles of earth is inverted to the
compass poles, compass north (also called
geographical north) is earthly south.
nationalmaglab.org
Magnetic Field and Its Lines
● Magnetic field is a volume of space where magnetism
is detected around a magnet
● Its shape, strength, and direction can be described
through lines
○ Shape is mostly elliptical but is connected to
opposite pole at the shortest distance.
○ Strongest areas / poles have to be described with
the most number of lines - closest one another
○ Lines originate at north and arrive at south
(described by an arrow)
Magnetic Field
Where an electric field
affects charges, a magnetic
field affects POLES.
A place that will cause a
magnetic pole to experience
a force is called MAGNETIC
FIELD
Drawing Field Lines
● Magnetic field lines are drawn from north
pole to south pole (indicated by an
arrow)
● Near the poles the lines are the closest
to each other
● No connection between the same poles
● No intersection between field lines
● Might be overlapped with other magnets
without neglecting the first four rules
schoolphysics.co.uk
Are the magnets in
the top picture are
same polarity or
opposite polarity?
Explain why?
How about the
bottom picture?
Uniform Field
● Normally, field lines are drawn elliptical very closely near the poles
and further away in the center parts of the magnet
● However, when N pole and S pole is close to each other, uniform
field of straight lines with same distance one another is observed
● The strength is equal at everywhere between the 2 poles
● Very important for further application of magnets
Magnetic flux density
Magnetic flux
density (B) is
the term
referring to the
strength of
magnetic field,
the unit is
Tesla (T).
Quantity of flux Φ
Quantity of
flux Φ
(measure
in Weber,
Wb)
Quantity of flux Φ
02
Electric Motor
Fleming’s Left Hand Rule
Fleming’s Left Hand Rule
03
Magnetic Forces
A. Magnetic Force in the
WIRE
B. Magnetic Force on
PARTICLE
The Mass
Spectromete
r
4. Generating Electricity
Transformers
Q3.