1. A 5.0-mC point charge is placed at the center of a cube. The electric flux in N × m2/C through one side of the cube is:
A.0
B.7.1 × 104
C.9.4 × 104
D.1.4 × 105
E.5.6 × 105


2. A 30-N/C uniform electric field points perpendicularly toward the left face of a large neutral conducting sheet. The area charge density on the left and right faces, respectively, are:
A.–2.7 × 10–9 C/m2; +2.7 × 10–9 C/m 2
B.+2.7 × 10–9 C/m2; –2.7 × 10–9 C/m 2
C.–5.3 × 10–9 C/m2; +5.3 × 10–9 C/m 2
D.+5.3 × 10–9 C/m2; –5.3 × 10–9 C/m 2
E.0; 0


3. A cylinder has a radius of 2.1 cm and a length of 8.8 cm. Total charge 6.1 × 10–7 C is distributed uniformly throughout. The volume charge density is:
A.5.3 × 10–5 C/m3
B.5.3 × 10–5 C/m2
C.8.5 × 10–4 C/m3
D.5.0 × 10–3 C/m3
E.6.3 × 10–2 C/m3


4. Positive charge Q is placed on a conducting spherical shell with inner radius R1 and outer radius R2. A point charge q is placed at the center of the cavity. The magnitude of the electric field at a point outside the shell, a distance r from the center, is:
A.
B.
C.q/4p50r2
D.(q + Q)/4p50r2
E.


5. Positive charge Q is placed on a conducting spherical shell with inner radius R1 and outer radius R2. A point charge q is placed at the center of the cavity. The magnitude of the electric field at a point in the cavity, a distance r from the center, is:
A.
B.
C.q/4p50r2
D.(q + Q)/4p50r2
E.


6. A spherical shell has an inner radius of 3.7 cm and an outer radius of 4.5 cm. If charge is distributed uniformly throughout the shell with a volume density of 6.1 × 10–4 C/m3 the total charge is:
A.1.0 × 10–7 C
B.1.3 × 10–7 C
C.2.0 × 10–7 C
D.2.3 × 10–7 C
E.4.0 × 10–7 C


7. A total charge of 6.3 × 10–8 C is distributed uniformly throughout a 2.7-cm radius sphere. The volume charge density is:
A.3.7 × 10–7 C/m3
B.6.9 × 10–6 C/m3
C.6.9 × 10–6 C/m2
D.2.5 × 10–4 C/m3
E.7.6 × 10–4 C/m3


8.

The table below gives the electric flux in N × m2/C through the ends and round surfaces of four gaussian surfaces in the form of cylinders. Rank the cylinders according to the charge inside, from the most negative to the most positive.



left end

right end

rounded surface


cylinder 1:

+2 ´ 10–9

+4 ´ 10–9

–6 ´ 10–9


cylinder 2:

+3 ´ 10–9

–2 ´ 10–9

+6 ´ 10–9


cylinder 3:

–2 ´ 10–9

–5 ´ 10–9

+3 ´ 10–9


cylinder 4:

+2 ´ 10–9

–5 ´ 10–9

–3 ´ 10–9



A.1, 2, 3, 4
B.4, 3, 2, 1
C.3, 4, 2, 1
D.3, 1, 4, 2
E.4, 3, 1, 2


9. A 3.5-cm radius hemisphere contains a total charge of 6.6 × 10–7 C. The flux through the rounded portion of the surface is 9.8 × 104 N × m2/C. The flux through the flat base is:
A.0
B.+2.3 × 104 N × m2/C
C.–2.3 × 104 N × m2/C
D.–9.8 × 104 N × m2/C
E.+9.8 × 104 N × m2/C


10. Charge is distributed uniformly on the surface of a large flat plate. The electric field 2 cm from the plate is 30 N/C. The electric field 4 cm from the plate is:
A.120 N/C
B.80 N/C
C.30 N/C
D.15 N/C
E.7.5 N/C


11. A physics instructor in an anteroom charges an electrostatic generator to 25 mC, then carries it into the lecture hall. The net electric flux in N × m2/C through the lecture hall walls is:
A.0
B.25 × 10–6
C.2.2 × 105
D.2.8 × 106
E.can't tell unless the lecture hall dimensions are given


12. Charge Q is distributed uniformly throughout a spherical insulating shell. The net electric flux in N × m2/C through the outer surface of the shell is:
A.0
B.Q/50
C.2Q/50
D.Q/450
E.Q/2p50


13.

Which of the following graphs represents the magnitude of the electric field as a function of the distance from the center of a solid charged conducting sphere of radius R?




A.I
B.II
C.III
D.IV
E.V


14. A positive point charge Q is placed outside a large neutral conducting sheet. At any point in the interior of the sheet the electric field produced by charges on the surface is directed:
A.toward the surface
B.away from the surface
C.toward Q
D.away from Q
E.none of the above


15. Consider Gauss's law: × d2 = q/50. Which of the following is true?
A.® must be the electric field due to the enclosed charge
B.If q = 0 then ® = 0 everywhere on the Gaussian surface
C.If the charge inside consists of an electric dipole, then the integral is zero
D.On the surface ® is everywhere parallel to d2
E.If a charge is placed outside the surface, then it cannot affect ® on the surface



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