Electricity and
Magnetism
http://www.youtube.com/watch?v=icfJWcwJtWU
http://www.youtube.com/watch?v=mGkU8cHHSMU
http://www.youtube.com/watch?v=icfJWcwJtWU
Nikola Tesla
• http://www.youtube.com/watch?v=FRjT9vQCG9E
Positive and negative charge
• Protons: have a positive charge and are in the
nucleus of an atom
• Electrons: have a negative charge and orbit an atom
• Neutrons: have a neutral charge and are in the
nucleus of an atom
• Atoms: have equal amounts of protons and
electrons so atoms have a neutral charge
Electrical Charge
• Law of conservation of charge: charge cannot be
created or destroyed, it can only be transferred
from one object to another
Electrical Charge
• Charges exert forces: Charges that are alike repel
each other
• Opposite charges attract each other
• http://www.stevespanglerscience.com/lab/videos#
?video=static-electricity-fly
Electrical Charge
• Electrical charge and force: as the electrical charge
increase, the electrical force increases
• Electric fields: every thing with an electrical charge
is surrounded by an electrical field
Gravity vs. Electricity
• The electrical force between 2 objects is much
stronger than gravity
• BUT because electrical charge is constantly being
transferred between objects, the electrical force
feels weaker than gravity
Conductors and Insulators
• Conductors and insulators: electrons are held
tightly in some atoms and not as tightly in other
atoms
Conductors
• Conductors: a material in which electrons are able
to move easily
• Examples: copper, metal, water
Insulators
• Insulators: a material in which electrons are not
able to move easily in
• Examples: plastic, wood, rubber, and glass
Charging Objects
• Charging by contact: the transferring of electrons
by touching or rubbing
Charging Objects
• Charging by
induction: the
rearranging of
electrons on a
neutral object
caused by a nearby
charged object
Transferring Electrical Charge
• Static Electricity: the accumulation of excess
electrical charge on an object
• Static Discharge: the transfer of charge between
two objects because of a build up of static
electricity
• Example: lightning
Lightning
• Lightning: a large static
Thunder
• Thunder: caused by the intense heat warming
the air from the lightning and making rise very
quickly causing a noise
• http://strangesounds.org/2013/07/amazing-technology-fantastic-videos-oflightning-strikes-slowed-down.html
• http://strangesounds.org/2013/07/amazing-technology-fantastic-videos-oflightning-strikes-slowed-down.html
• http://www.youtube.com/watch?v=RLWIBrweSU8
Detecting electrical charge
• Electroscope: an instrument to detect electrical
charge
Electrical Current
• Electrical current: the movement of electric charges
in a single direction
• Measured in amperes
• One ampere = 6250 million electrons moving past a
single point every second
Voltage difference
• Voltage difference: electrical charge flows from a
higher voltage to a lower voltage which keeps the
electrical flow going
• Measured in volts