created by Sabrina
Thursday 2 August 2012
Tuesday 31 July 2012
Grounding-the Removal of a Charge
Grounding is a process of removing a charge from an object. It means that it transfers the electrical charge from an object to the ground making it neutral. Electroscope connected to a conducting pathway to another object that receive electron. This process works because electrons find another electrons. They repel each other. If the electroscope is positive charge, it will the electron from other object. So it’s become neutral.
picture courtesy from: http://www.nachi.org/grounding-electrodes.htm
picture courtesy from: http://groundlevelsystems.com/electrical-ground-testing
created by Roland
edited by Ghani and Roland
Charging by Conduction
Charging by conduction is a charge that involves a contact between
a charge objects with a neutral object.
When the negative charges get in contact with the neutral charges.
For example; when negative charges steel stick will get in contact with the
neutral charge iron plate, the electron in the steel stick will move to the
iron plate neutral zone area. It’s because electron repel each other or in
other word the electrons are trying to stay as far as possible from the other
electrons. So when there is a neutral charge area inside the iron plate the
electrons will immediately move to the neutral charge area make the iron plate
become negative charge due to number of negative charge exceeding the number of
positive charges.
example of animation: http://education.uoit.ca/lordec/ID_LORDEC/electroscope/
*click the option students and choose charging by induction
There also conduction for positive charge, even though the process
is a bit different. For example there is positive charge steel ruler and a
neutral charge iron plate. When both of them get in contact or touching each
other, the proton in the ruler will start to attract the electrons in the
plate. It’s because proton cannot move like electron but can attract the
electrons to proton itself. It also decreases the number of electron on the
plate making it a positive charge plate, due to the number of electrons has
been decrease making it less than the proton.
picture courtesy from:
http://www.physicsclassroom.com/class/estatics/u8l2c1.gif
picture courtesy from:http://www.energex.com.au/switched_on/images/content/senior_school/us10_pic.jpg
http://www.youtube.com/watch?v=xClT7LIRmls
created by Brainhart
edited by Sabrina
Charging by Induction
Charging by induction is a method
of charging an object without touching the object to any other charged object
and using insulating objects to prevent any conduction other than the object
that is being charged. Induction uses the process of polarization and
insulation and a bit of conduction.
A common demonstration would be 2
metal balls and a charged object. The 2 metal objects are conductors and they
have neutral charge. While for example, a negative charged balloon will
polarize the metal balls and move the electrons from 1 ball to the other making
positive and negative charge. The insulator stand will prevent the charge from
going to the ground which will neutralize the charge.
Another demonstration that
relates to the grounding system is nearly the same demonstration as the
previous, but with only 1 metal ball, a charged balloon, and a grounding wire
(your body/arm can be used as a grounding system as long as your feet are at
the ground). The balloon can be charged in anyway, positive or negative. As the
charged balloon polarizes the metal ball, the electron will move to the
grounding wire/your arm and moves to the ground making the metal ball electric
charged. If the balloon is a positive charged object then the metal ball will
be a negative charged object, and vice versa.
photo courtesy from: http://www.kirksville.k12.mo.us/khs/teacher_web/alternative/negatively_charged_rod.jpg
photo courtesy from: http://scratch.mit.edu/static/projects/dapontes/1741829_med.png
video courtesy: fahyscience's channel
created by Ghani
edited by Sabrina
Charging by Friction
As it is explained, that all of
the objects are made of different types of atoms and combination of different
atoms. The presence of atoms give objects electrical behavior one of thee
properties known as electron affinity, this behavior is referring to the amount
of attraction force of one electron for one another, which is one of the
process of charging, that is charging my friction or well known as rubbing.
picture courtesy from: http://www.ipodphysics.com/forces-field-create-a-charge.php
For example of the charging by
friction, balloon that is rubbed with our hair, the electrons that are stable
in the balloon will be attracted to the ones in our hair, or it can be opposite
that the electrons from our hair is attracted to the ones in the balloon, since
either of the objects has lose or gain electrons, they will be more attracted
to each other because the one that loses electrons, will become positive charge
and the one who gained electrons will be negative charged. For example if we
put then close to each other, the balloon will move and will be closer to our
hair or the hair will go up to touch the balloon.
picture courtesy from: http://etorgerson.net/B10_Static.html
Frictional charging is a process
that transfers electrons to the other object by rubbing them together, if one
of the objects has greater attraction force, then the object will take the
electrons of the weaker force. For the object that gains electrons will have
excess of electrons and become negative charged because the number of electrons
is too much and the one that loses becomes positive since the amount of proton
is greater.
picture courtesy from: http://www.sciencesource2.ca/resources/hotpotato_quiz_09_10_1.htm
video courtesy: fahyscience's channel
created by Sabrina
edited by Sabrina
edited by Sabrina
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