Download Electric Field Strength

5.3 Electric Field Strength
What is a Field?
An electric field is a region of space in which a charged object is acted upon by a
force. The electric field shows the direction that a small positive test charge would
move in a region of an electric field.
Positive Charge
Negative Charge
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5.3 Electric Field Strength
Electric Fields around pairs of Point Charges:
Uniform Electric Field
between two oppositely
charged plates:
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5.3 Electric Field Strength
Defining Electric Field
Electric Field Strength is defined as electric force per charge.
E=
Fe
{Units: N/C}
Q
Magnitude of Electric Field around a Source Charge
Bringing electric force into the equations gives you:
Fe =
k Q1Q2
r2
E=
kQ
R2
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5.3 Electric Field Strength
Multiple Charges Creating Electric Fields:
The electric fields created by 2 or more charges are dealt with by adding the
individually electric fields as vectors.
+q1
P
E2
E1
+Q2
Enet = E2 – E1
(At point P)
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5.3 Electric Field Strength
Key Questions
In this section, you should understand how to solve the following key questions.
Page 181 – Practice Problem 5.3.1: #2
Page 182 – Quick Check #3
Page 181 – Practice Problem 5.3.2: #2
Page 185 - 186 – Review 5.3 #2,4,6,8, & 10