3. A negatively charged particle is moving in the +x-direction when it enters a ... Two particles, each having a mass of 3.0 mg and having equal but opposite.
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Phys222 W15 Practice Exam 2: Chapters 23-27 Keys Name: ___________________________________________________________ Please mark your answer clearly here and bubble in the scantron!
1.
Three identical point charges Q are placed at the vertices of an equilateral triangle (length of each side = 2.0 m). If Q = 60 µC, what is the magnitude of the electrostatic force on any one of the charges? a. b. c. d. e.
2.
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A charge (uniform linear density = 9.0 nC/m) is distributed along the x axis from x = 0 to x = 3.0 m. Determine the magnitude of the electric field at a point on the x axis with x = 4.0 m. a. b. c. d. e.
3.
25 N 19 N 14 N 22 N 16 N
81 N/C 74 N/C 61 N/C 88 N/C 20 N/C
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A negatively charged particle is moving in the +x-direction when it enters a region with a uniform electric field pointing in the +x-direction. Which graph gives its position as a function of time correctly? (Its initial position is x = 0 at t = 0.) c <= x
x
t
t
(a)
4.
x
x
(b)
x
t
t
(d)
(c)
t
(e)
A charge of 0.80 nC is placed at the center of a cube that measures 4.0 m along each edge. What is the electric flux through one face of the cube? a. b. c. d. e.
90 N ⋅ m2/C 15 N ⋅ m2/C 45 N ⋅ m2/C 23 N ⋅ m2/C 64 N ⋅ m2/C
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Phys222 W15 Practice Exam 2: Chapters 23-27 Keys 5.
A positive point charge q is placed at the center of an uncharged metal sphere insulated from the ground. The outside of the sphere is then grounded as shown. Then the ground wire is removed. A is the inner surface and B is the outer surface. Which statement is correct?
q
a. b. c. d. e. 6.
The charge on A is –q; that on B is +q. The charge on B is –q; that on A is +q. q The charge is on A and on B. 2 There is no charge on either A or B. The charge on A is –q; there is no charge on B.
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A particle (charge = 50 µC) moves in a region where the only force on it is an electric force. As the particle moves 25 cm from point A to point B, its kinetic energy increases by 1.5 mJ. Determine the electric potential difference, V B − V A . a. b. c. d. e.
7.
AB
–50 V –40 V –30 V –60 V +15 V
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Two particles, each having a mass of 3.0 mg and having equal but opposite charges of magnitude 5.0 nC, are released simultaneously from rest when the two are 5.0 cm apart. What is the speed of either particle at the instant when the two are separated by 2.0 cm? a. b. c. d. e.
2.1 m/s 1.5 m/s 1.8 m/s 2.4 m/s 3.2 m/s
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Phys222 W15 Practice Exam 2: Chapters 23-27 Keys 8.
Determine the energy stored by C4 when C1 = 20 µF, C2 = 10 µF, C3 = 14 µF, C4 = 30 µF, and V0 = 45 V. C2
C3 C1
C4 +
– V0
a. b. c. d. e. 9.
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A wire (length = 2.0 m, diameter = 1.0 mm) has a resistance of 0.45Ω. What is the resistivity of the material used to make the wire? a. b. c. d. e.
10.
3.8 mJ 2.7 mJ 3.2 mJ 2.2 mJ 8.1 mJ
5.6 × 10–7 Ω ⋅ m 1.2 × 10–7 Ω ⋅ m 1.8 × 10–7 Ω ⋅ m 2.3 × 10–7 Ω ⋅ m 7.1 × 10–7 Ω ⋅ m
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Light bulb A is rated at 60 W and light bulb B is rated at 100 W. Both are designed to operate at 110 V. Which statement is correct? a. b. c. d. e.
The 60 W bulb has a greater resistance and greater current than the 100 W bulb. The 60 W bulb has a greater resistance and smaller current than the 100 W bulb. <= The 60 W bulb has a smaller resistance and smaller current than the 100 W bulb. The 60 W bulb has a smaller resistance and greater current than the 100 W bulb. We need to know the resistivities of the filaments to answer this question.
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Phys222 W15 Practice Exam 2: Chapters 23-27 Keys Open-ended 11. The electric field in the region of space shown is given by E = (8i + Byzj) N/C, -2 where B = 2 m . What is the magnitude of the electric flux through the top face of the cube shown in Fig. 1? y 2m