Ch23 - University Physics 15th edition PDF

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University Physics 15th edition...

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A23.1

When a positive charge moves in the direction of the electric field,

+q

Motion

A. the field does positive work on it and the potential energy increases. B. the field does positive work on it and the potential energy decreases.

C. the field does negative work on it and the potential energy increases. D. the field does negative work on it and the potential energy decreases. E. the field does zero work on it and the potential energy remains constant. © 2020 Pearson Education, Inc.

A23.2

When a positive charge moves opposite to the direction of the electric field,

Motion

+q

A. the field does positive work on it and the potential energy increases. B. the field does positive work on it and the potential energy decreases. C. the field does negative work on it and the potential energy increases. D. the field does negative work on it and the potential energy decreases.

E. the field does zero work on it and the potential energy remains constant. © 2020 Pearson Education, Inc.

A23.3

When a negative charge moves in the direction of the electric field,

–q

Motion

A. the field does positive work on it and the potential energy increases. B. the field does positive work on it and the potential energy decreases.

C. the field does negative work on it and the potential energy increases. D. the field does negative work on it and the potential energy decreases. E. the field does zero work on it and the potential energy remains constant. © 2020 Pearson Education, Inc.

A23.4 When a negative charge moves opposite to the direction of the electric field,

Motion

–q

A. the field does positive work on it and the potential energy increases. B. the field does positive work on it and the potential energy decreases.

C. the field does negative work on it and the potential energy increases. D. the field does negative work on it and the potential energy decreases. E. the field does zero work on it and the potential energy remains constant. © 2020 Pearson Education, Inc.

A23.5 The electric potential energy of two point charges approaches zero as the two point charges move farther away from each other. If the three point charges shown here lie at the vertices of an equilateral triangle, the electric potential energy of the system of three charges is

A. positive. B. negative. C. zero. D. either positive or negative. E. either positive, negative, or zero. © 2020 Pearson Education, Inc.

Charge #2 +q Charge #1 +q y –q

x

Charge #3

A23.6 The electric potential energy of two point charges approaches zero as the two point charges move farther away from each other. If the three point charges shown here lie at the vertices of an equilateral triangle, the electric potential energy of the system of three charges is

A. positive. B. negative. C. zero. D. either positive or negative. E. either positive, negative, or zero. © 2020 Pearson Education, Inc.

Charge #2 –q Charge #1 +q y –q

x

Charge #3

A23.7 The electric potential due to a point charge approaches zero as you move farther away from the charge. If the three point charges shown here lie at the vertices of an equilateral triangle, the electric potential at the center of the triangle is

Charge #2 +q Charge #1 +q y –q

A. positive. B. negative.

C. zero. D. either positive or negative.

E. either positive, negative, or zero. © 2020 Pearson Education, Inc.

x

Charge #3

A23.8 The electric potential due to a point charge approaches zero as you move farther away from the charge. If the three point charges shown here lie at the vertices of an equilateral triangle, the electric potential at the center of the triangle is

Charge #2 –q Charge #1 +q y –q

A. positive. B. negative. C. zero. D. either positive or negative. E. either positive, negative, or zero. © 2020 Pearson Education, Inc.

x

Charge #3

A23.9 Consider a point P in space where the electric potential is zero. Which statement is correct?

A. A positive point charge placed at point P would feel no electric force. B. A positive point charge placed at point P would feel an electric force, but nothing can be said about the direction of the force. C. A positive point charge placed near point P would feel an electric force pulling it toward P.

D. A positive point charge placed near point P would feel an electric force pushing it away from P. E. More than one of the above is possible. © 2020 Pearson Education, Inc.

A23.10 Where an electric field line crosses an equipotential surface, the angle between the field line and the equipotential is

A. zero.

B. between zero and 90°. C. 90°.

D. either A or C. E. either A, B, or C.

© 2020 Pearson Education, Inc.

A23.11 A solid spherical conductor has a spherical cavity in its interior. The cavity is not centered on the center of the conductor. If there is a net positive charge on the conductor, the electric field in the cavity

Conductor

Cavity

A. points generally from the center of the conductor toward the outermost surface of the conductor. B. points generally from the outermost surface of the conductor toward the center of the conductor.

C. is uniform and nonzero. D. is zero.

E. cannot be determined from information given. © 2020 Pearson Education, Inc.

A23.12 What is the direction of the electric potential gradient at a certain point?

A. the same as the direction of the electric field at that point B. opposite to the direction of the electric field at that point

C. perpendicular to the direction of the electric field at that point D. at an angle other than 0°, 90°, or 180° from the direction of the electric field at that point E. more than one of the above

© 2020 Pearson Education, Inc.

A-RT23.1 Two point charges, +q and –q, are placed as shown. Rank the five points labeled A, B, C, D, and E in order of the electric potential at each point due to the two point charges, from most positive to most negative. The five points and the two point charges all lie in the same plane.

A C

B D

+q

E

–q

Answer: CADBE

© 2020 Pearson Education, Inc....