# Phyc 260 Solutions

Topics: Electric charge, Charge density, Electrostatics Pages: 28 (5515 words) Published: February 12, 2013
Chapter 24
Gauss’s Law

Multiple Choice

1.Two charges of 15 pC and –40 pC are inside a cube with sides that are of 0.40-m length. Determine the net electric flux through the surface of the cube.

a.+2.8 N ( m2/C
b.–1.1 N ( m2/C
c.+1.1 N ( m2/C
d.–2.8 N ( m2/C
e.–0.47 N ( m2/C

2.The total electric flux through a closed cylindrical (length = 1.2 m, diameter = 0.20 m) surface is equal to –5.0 N ( m2/C. Determine the net charge within the cylinder.

a.–62 pC
b.–53 pC
c.–44 pC
d.–71 pC
e.–16 pC

3.Charges q and Q are placed on the x axis at x = 0 and x = 2.0 m, respectively. If q = –40 pC and Q = +30 pC, determine the net flux through a spherical surface (radius = 1.0 m) centered on the origin.

a.–9.6 N ( m2/C
b.–6.8 N ( m2/C
c.–8.5 N ( m2/C
d.–4.5 N ( m2/C
e.–1.1 N ( m2/C

4.A uniform linear charge density of 4.0 nC/m is distributed along the entire x axis. Consider a spherical (radius = 5.0 cm) surface centered on the origin. Determine the electric flux through this surface.

a.68 N ( m2/C
b.62 N ( m2/C
c.45 N ( m2/C
d.79 N ( m2/C
e.23 N ( m2/C

5.A uniform charge density of 500 nC/m3 is distributed throughout a spherical volume (radius = 16 cm). Consider a cubical (4.0 cm along the edge) surface completely inside the sphere. Determine the electric flux through this surface.

a.7.1 N ( m2/C
b.3.6 N ( m2/C
c.12 N ( m2/C
d.19 N ( m2/C
e.970 N ( m2/C

6.A point charge +Q is located on the x axis at x = a, and a second point charge –Q is located on the x axis at x = –a. A Gaussian surface with radius r = 2a is centered at the origin. The flux through this Gaussian surface is

a.zero because the negative flux over one hemisphere is equal to the positive flux over the other. b.greater than zero.
c.zero because at every point on the surface the electric field has no component perpendicular to the surface. d.zero because the electric field is zero at every point on the surface. e.none of the above.

7.The xy plane is “painted” with a uniform surface charge density which is equal to 40 nC/m2. Consider a spherical surface with a 4.0-cm radius that has a point in the xy plane as its center. What is the electric flux through that part of the spherical surface for which z > 0?

a.14 N ( m2/C
b.11 N ( m2/C
c.17 N ( m2/C
d.20 N ( m2/C
e.23 N ( m2/C

8.A long cylinder (radius = 3.0 cm) is filled with a nonconducting material which carries a uniform charge density of 1.3 µC/m3. Determine the electric flux through a spherical surface (radius = 2.0 cm) which has a point on the axis of the cylinder as its center.

a.5.7 N ( m2/C
b.4.9 N ( m2/C
c.6.4 N ( m2/C
d.7.2 N ( m2/C
e.15 N ( m2/C

9.Charge of uniform surface density (4.0 nC/m2) is distributed on a spherical surface (radius = 2.0 cm). What is the total electric flux through a concentric spherical surface with a radius of 4.0 cm?

a.2.8 N ( m2/C
b.1.7 N ( m2/C
c.2.3 N ( m2/C
d.4.0 N ( m2/C
e.9.1 N ( m2/C

10.A charge of uniform volume density (40 nC/m3) fills a cube with 8.0-cm edges. What is the total electric flux through the surface of this cube?

a.2.9 N ( m2/C
b.2.0 N ( m2/C
c.2.6 N ( m2/C
d.2.3 N ( m2/C
e.1.8 N ( m2/C

11.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.90 N ( m2/C
b.15 N ( m2/C
c.45 N ( m2/C
d.23 N ( m2/C
e.64 N ( m2/C

12.A hemispherical surface (half of a spherical surface) of radius R is located in a uniform electric field of magnitude E that is parallel to the axis of the...