PHY 131 EXAM 2 | QUESTIONS AND
ANSWERS | 2026 UPDATE | WITH
COMPLETE SOLUTIONS
1. The electric field at the surface of a positively charged conductor has a direction characterized by which of the
following?
a. tangent to the surface
b. perpendicular inward toward the charge
c. at a 45° angle to the surface
d. perpendicular outward and away from the charge - ANSWER>d
2. Which of the following best characterizes electrical insulators?
a. charges on the surface don't move
b. high tensile strength
c. electric charges move freely
d. good heat conductors - ANSWER>a
3. The electric field associated with a uniformly charged hollow metallic sphere is the greatest at:
,a. the center of the sphere.
b. the sphere's inner surface.
c. infinity.
d. the sphere's outer surface. - ANSWER>d
4. If a conductor is in electrostatic equilibrium near an electrical charge:
a. the total charge on the conductor must be zero.
b. the electric field inside the conductor must be zero.
c. any charges on the conductor must be uniformly distributed.
d. the sum of all forces between the conductor and the charge must be zero. - ANSWER>b
5. Electric field is dimensionally equivalent to which of the following?
a. N⋅m/C
b. N/C
c. N⋅m2/C2
d. N/C2 - ANSWER>b
, 6. If the size of the charge value is tripled for both of two point charges maintained at a constant separation, the
mutual force between them will be changed by what factor?
a. 9
b. 3
c. 1/3
d. 1/9
e. 1 - ANSWER>a
7. A thin uncharged conducting spherical shell has a charge q carefully placed at its center through a small hole in
the shell. The charge q does not touch the shell. What is the charge on the outer surface of the shell?
a. q
b. −q
c. 2q
d. 0 - ANSWER>a
8. The constant ke, which appears in Coulomb's law formula, is equivalent dimensionally to which of the following?
a. N⋅m/C
ANSWERS | 2026 UPDATE | WITH
COMPLETE SOLUTIONS
1. The electric field at the surface of a positively charged conductor has a direction characterized by which of the
following?
a. tangent to the surface
b. perpendicular inward toward the charge
c. at a 45° angle to the surface
d. perpendicular outward and away from the charge - ANSWER>d
2. Which of the following best characterizes electrical insulators?
a. charges on the surface don't move
b. high tensile strength
c. electric charges move freely
d. good heat conductors - ANSWER>a
3. The electric field associated with a uniformly charged hollow metallic sphere is the greatest at:
,a. the center of the sphere.
b. the sphere's inner surface.
c. infinity.
d. the sphere's outer surface. - ANSWER>d
4. If a conductor is in electrostatic equilibrium near an electrical charge:
a. the total charge on the conductor must be zero.
b. the electric field inside the conductor must be zero.
c. any charges on the conductor must be uniformly distributed.
d. the sum of all forces between the conductor and the charge must be zero. - ANSWER>b
5. Electric field is dimensionally equivalent to which of the following?
a. N⋅m/C
b. N/C
c. N⋅m2/C2
d. N/C2 - ANSWER>b
, 6. If the size of the charge value is tripled for both of two point charges maintained at a constant separation, the
mutual force between them will be changed by what factor?
a. 9
b. 3
c. 1/3
d. 1/9
e. 1 - ANSWER>a
7. A thin uncharged conducting spherical shell has a charge q carefully placed at its center through a small hole in
the shell. The charge q does not touch the shell. What is the charge on the outer surface of the shell?
a. q
b. −q
c. 2q
d. 0 - ANSWER>a
8. The constant ke, which appears in Coulomb's law formula, is equivalent dimensionally to which of the following?
a. N⋅m/C
