Download PHYSICS 10 a,b,c

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PHYSICS 10 a,b,c
Chapter 8.01 to 8.03
Electric Charge and Fields
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Electric Charge
 Charge is Conserved. Only Electrons are Transferred.
 Charge is Quantized. Electric charge has the symbol q.
 There are only two types of charges: + and − .
 Example: q = − e (An electron)
 Example: q = + e ( A proton)
 Some particles have NO charge, such as a Neutron.
 The Electric Force, FE , decreases as the distance
between two charges increases.
 Opposites Attract, but charges of the same type Repel.
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Induced Charge on an Object
 Conductor: A material where charge moves freely.
 Insulator: A material where negative charge is not
transferred easily to another object.
 Semi-conductor: Special material that can become a
conductor at high temperatures. At low temperature it may
be an insulator.
 Induction: The process of making a neutrally-charged
object polarized. Polarization is the separation of
charges into plus areas and negative areas. No contact
between objects is required.
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Electric Field
 An Electric Field exists everywhere charged particles
exist, just as the Gravitational Field exists at all points in
the Universe where there is a mass.
 The Electric Field points from Positive Charge to Negative
Charge (always).
 Negative Charge accumulates at sharp points on objects,
so the Electric Field is stronger at those points than
elsewhere on the object.
 The Electric Force is directly proportional to the
Electric Field. In fact, FE = q∙E.
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A few questions now!
1. The diagram below depicts a point charge. Which
way would a small positive test charge move?:
e-
+q
a. Left
b.Right
c. Out of the screen (Towards you)
d.Into the screen (Away from you)
e.None of these choices are correct
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A few questions now!
2. The diagram below depicts an Electric Field, E.
Which way would a small positive test charge
move?:
E
+q
a.
b.
c.
d.
e.
Left
Right
Out of the screen (Towards you)
Into the screen (Away from you)
None of these choices are correct