SNC1W7 By Megan
CHARGING STATIC (PART 2)
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LEARNING GOALS
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I can demonstrate an understanding of
the principles of static and current
electricity.
I can explain the characteristics of
conductors and insulators and how
materials allow static charge to build
up or be discharged.
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THERE ARE 3 METHODS IN CHARGING
STATICS:
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by Friction
by Contact (Conduction)
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by Induction
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CHARGING BY INDUCTION
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Charging a neutral object by bringing
another charged object close to, but not
touching , the neutral object
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(i) INDUCED CHARGE SEPARATION
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When a charged object is close to, but not
touching, a neutral object, the neutral object
can have a positive end and a negative
end (charge separation)
The “like” charges will be repelled from the
induction point, and the opposite charges
will be attracted to the induction point.
The object’s overall charge will remain
neutral .
When the charged object is removed, the
object will return to neutral
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EXAMPLE 1:
DRAW HOW CHARGES ON THE OBJECT MOVE DURING
AND AFTER THE INDUCTION.
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EXAMPLE 1:
DRAW HOW CHARGES ON THE OBJECT MOVE DURING
AND AFTER THE INDUCTION.
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GROUNDING:
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Grounding: When a charged object
touches a large body such as Earth, it will
remove the charge on the object and
return it to neutral.
The reason is that Earth is very big and it
can gain or lose electron without any
effect.
(The symbol for grounding is shown on the
left side.)
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(ii) INDUCED CHARGE SEPARATION +
GROUNDING (CHARGING BY INDUCTION)
Electroscope Animation
? When a charged object is close to, but not
touching, a grounded neutral object, the
neutral object can gain or lose electrons
from the ground.
? If the ground is NOT removed and the
charged object is removed, the neutral object
will remain neutral.
? If the ground is removed before the charged
object is removed, the neutral object will gain
an electric charge.
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Example 2: Draw how charges on the object move
during and after the induction if ground is NOT
removed.
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Example 3: Charging by Induction (Ground is removed
before the charged object)
Draw how charges on the object move during and after the
induction if ground is REMOVED before the charged object.
Before Induction
During Induction
After Induction
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Draw a series of diagrams showing how the pithball electroscope can be charged permanently by
INDUCTION using a negatively charged rod
When a negatively
charged ebonite rod
is brought near a
neutral pith ball, the
electrons on the pith
ball are repelled and
it becomes
temporarily
negatively charged
on its right side.
Attaching a
ground wire to the
pith ball conducts
the repelled
electron on the
right side into the
ground.
After removing
the ground wire,
the pith ball
remains
permanently
positively
charged.
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