a spherical gaussian surface (#1) encloses and is centered...

A spherical Gaussian surface (#1)encloses and is centered on a pointcharge +q. A second sphericalGaussian surface (#2) of the samesize also encloses the charge but isnot centered on it.

Compared to the electric fluxthrough surface #1, the flux throughsurface #2 is

A. greater. B. the same.

C. less, but not zero. D. zero.

E. not enough information given todecide

Q22.1

+q

Gaussiansurface #1

Gaussiansurface #2

A spherical Gaussian surface (#1)encloses and is centered on a pointcharge +q. A second sphericalGaussian surface (#2) of the samesize also encloses the charge but isnot centered on it.

Compared to the electric fluxthrough surface #1, the flux throughsurface #2 is

A. greater. B. the same.

C. less, but not zero. D. zero.

E. not enough information given todecide

A22.1

+q

Gaussiansurface #1

Gaussiansurface #2

Two point charges,+q (in red) and –q(in blue), arearranged as shown.

Through whichclosed surface(s) isthe net electric fluxequal to zero?

A. surface A only B. surface B only

C. surface C only C. surface D only

D. both surface C and surface D

Q22.2

Two point charges,+q (in red) and –q(in blue), arearranged as shown.

Through whichclosed surface(s) isthe net electric fluxequal to zero?

A. surface A only B. surface B only

C. surface C only C. surface D only

D. both surface C and surface D

A22.2

A conducting spherical shell with innerradius a and outer radius b has apositive point charge Q located at itscenter. The total charge on the shell is–3Q, and it is insulated from itssurroundings. In the region a < r < b,

A. the electric field points radially outward.

B. the electric field points radially inward.

C. is zero.

D. not enough information given to decide

Q22.3

A conducting spherical shell with innerradius a and outer radius b has apositive point charge Q located at itscenter. The total charge on the shell is–3Q, and it is insulated from itssurroundings. In the region a < r < b,

A. the electric field points radially outward.

B. the electric field points radially inward.

C. is zero.

D. not enough information given to decide

A22.3

A conducting spherical shell with innerradius a and outer radius b has apositive point charge Q located at itscenter. The total charge on the shell is–3Q, and it is insulated from itssurroundings. How much charge residesin the inner surface (r=a)?

A. zero.

B. -1.5 Q .

C. - Q.

D. not enough information given to decide

Q22.4

A conducting spherical shell with innerradius a and outer radius b has apositive point charge Q located at itscenter. The total charge on the shell is–3Q, and it is insulated from itssurroundings. How much charge residesin the inner surface (r=a)?

A. zero.

B. -1.5 Q .

C. - Q.

D. not enough information given to decide

A22.4

A conducting spherical shell with innerradius a and outer radius b has a positivepoint charge Q located at its center. Thetotal charge on the shell is –3Q, and it isinsulated from its surroundings. What isthe force on a test charge (q) locatedoutside the shell at the distance r fromthe center (r > b) ?

A. zero.

B. kqQ/r2, pointing outward

C. kq(3Q)/r2 , pointing inward

D. kq(2Q)/r2 , pointing inward

Q22.5

A conducting spherical shell with innerradius a and outer radius b has a positivepoint charge Q located at its center. Thetotal charge on the shell is –3Q, and it isinsulated from its surroundings. What isthe force on a test charge (q) locatedoutside the shell at the distance r fromthe center (r > b) ?

A. zero.

B. kqQ/r2, pointing outward

C. kq(3Q)/r2 , pointing inward

D. kq(2Q)/r2 , pointing inward

A22.5

A conducting spherical shell with innerradius a and outer radius b has a positivepoint charge Q located at off-center. Thetotal charge on the shell is –3Q, and it isinsulated from its surroundings. What isthe force on a test charge (q) locatedoutside the shell at the distance r fromthe center (r > b) ?

A. Not enough information to decide

B. kqQ/r2, pointing outward

C. kq(3Q)/r2 , pointing inward

D. kq(2Q)/r2 , pointing inward

Q22.6

A conducting spherical shell with innerradius a and outer radius b has a positivepoint charge Q located at off-center. Thetotal charge on the shell is –3Q, and it isinsulated from its surroundings. What isthe force on a test charge (q) locatedoutside the shell at the distance r fromthe center (r > b) ?

A. Not enough information to decide

B. kqQ/r2, pointing outward

C. kq(3Q)/r2 , pointing inward

D. kq(2Q)/r2 , pointing inward

A22.6

For which of the following charge distributions wouldGauss’s law not be useful for calculating the electric field?

A. a uniformly charged sphere of radius R

B. a spherical shell of radius R with charge uniformlydistributed over its surface

C. a circular cylinder of radius R and height h withcharge uniformly distributed over its surface

D. an infinitely long circular cylinder of radius R withcharge uniformly distributed over its surface

E. Gauss’s law would be useful for finding the electricfield in all of these cases.

Q22.7

For which of the following charge distributions wouldGauss’s law not be useful for calculating the electric field?

A. a uniformly charged sphere of radius R

B. a spherical shell of radius R with charge uniformlydistributed over its surface

C. a circular cylinder of radius R and height h withcharge uniformly distributed over its surface

D. an infinitely long circular cylinder of radius R withcharge uniformly distributed over its surface

E. Gauss’s law would be useful for finding the electricfield in all of these cases.

A22.7