Download An Induced Electric Dipole

An Induced Electric Dipole
© 2010 Pearson Education, Inc.
Slide 20-20
Dipole and Uniform Electric Fields
© 2010 Pearson Education, Inc.
Slide 20-45
Checking Understanding
A set of electric field lines is directed as below. At which of the
noted points is the magnitude of the field the greatest?
© 2010 Pearson Education, Inc.
Slide 20-46
Answer
A set of electric field lines is directed as below. At which of the
noted points is the magnitude of the field the greatest?
A
© 2010 Pearson Education, Inc.
Slide 20-47
Electric Field Lines
© 2010 Pearson Education, Inc.
Slide 20-50
Conductors and Electric Fields
© 2010 Pearson Education, Inc.
Slide 20-55
Forces and Torques on Charges in Electric Fields
© 2010 Pearson Education, Inc.
Slide 20-56
Checking Understanding
A dipole is held motionless in a uniform electric field. For the
situation below, when the dipole is released, which of the following
describes the subsequent motion?
A.  The dipole moves to the right.
B.  The dipole moves to the left.
C.  The dipole rotates clockwise.
D.  The dipole rotates counterclockwise.
E.  The dipole remains motionless.
© 2010 Pearson Education, Inc.
Slide 20-57
Answer
A dipole is held motionless in a uniform electric field. For the
situation below, when the dipole is released, which of the following
describes the subsequent motion?
A.  The dipole moves to the right.
B.  The dipole moves to the left.
C.  The dipole rotates clockwise.
D.  The dipole rotates counterclockwise.
E.  The dipole remains motionless.
© 2010 Pearson Education, Inc.
Slide 20-58
Checking Understanding
A dipole is held motionless in a uniform electric field. For the
situation below, when the dipole is released, which of the following
describes the subsequent motion?
A.  The dipole moves to the right.
B.  The dipole moves to the left.
C.  The dipole rotates clockwise.
D.  The dipole rotates counterclockwise.
E.  The dipole remains motionless.
© 2010 Pearson Education, Inc.
Slide 20-59
Answer
A dipole is held motionless in a uniform electric field. For the
situation below, when the dipole is released, which of the following
describes the subsequent motion?
A.  The dipole moves to the right.
B.  The dipole moves to the left.
C.  The dipole rotates clockwise.
D.  The dipole rotates counterclockwise.
E.  The dipole remains motionless.
© 2010 Pearson Education, Inc.
Slide 20-60
Example Problem
A housefly walking across a clean surface can accumulate a
significant positive or negative charge. In one experiment, the
largest positive charge observed was +73 pC. A typical housefly
has a mass of 12 mg.
A.  Explain how a housefly could accumulate an electric charge by
walking across a surface.
B.  What magnitude and direction electric field would be necessary
to “levitate” a housefly with a maximum charge? Could such a
field exist in air?
© 2010 Pearson Education, Inc.
Slide 20-63
Summary
© 2010 Pearson Education, Inc.
Slide 20-64
Additional Example Problems
1.  A positively charged particle is motionless in the center of a
capacitor. Describe the subsequent motion of the charged
particle.
© 2010 Pearson Education, Inc.
Slide 20-69
Additional Example Problems
2.  Determine the magnitude and the direction of the electric field
at point A.
3.  Determine the individual forces and the net force on charge B
for each of the following cases.
© 2010 Pearson Education, Inc.
Slide 20-70