![Picture](/uploads/2/2/1/7/22171856/4784647_orig.png)
1. A hollow metal ring of radius r carries charge q. Consider an axis straight through the center of the ring. At what point(s) along this axis is/are the electric field equal to zero?
A.Only at the center of the ring
B.Only at the center of the ring, and a very long distance away
C.Only a very long distance away
D.Only at the center of the ring, a distance r away from the center, and a very long distance away
2. A conducting circular disk has a uniform positive surface charge density. Which of the following diagrams best represents the electric field lines from the disk? (The disk is drawn as a cross–section.)
A. 1
B. 2
C. 3
D. 4
E. None of the diagrams.
A. 1
B. 2
C. 3
D. 4
E. None of the diagrams.
![Picture](/uploads/2/2/1/7/22171856/8804677_orig.png)
3. An infinite plane lies in the yz-plane and it has a uniform surface charge density. The
electric field at a distance x from the plane is
A. decreases linearly with x.
B. decreases as 1/x2.
C. is constant and does not depend on x.
D. increases linearly with x.
E. is undetermined.
4. Rank the electric field strength in order from largest to smallest.
A: E1 < E2 < E3 = E4
B: E3 = E4 < E2 < E1
C: E2 = E3 < E4 < E1
D: E1 < E4 < E2 = E3
5. A solid conducting sphere has radius R and carries positive charge Q. Which of the following graphs represents the electric field E as a function of the distance r from the center of the sphere?
A. decreases linearly with x.
B. decreases as 1/x2.
C. is constant and does not depend on x.
D. increases linearly with x.
E. is undetermined.
4. Rank the electric field strength in order from largest to smallest.
A: E1 < E2 < E3 = E4
B: E3 = E4 < E2 < E1
C: E2 = E3 < E4 < E1
D: E1 < E4 < E2 = E3
5. A solid conducting sphere has radius R and carries positive charge Q. Which of the following graphs represents the electric field E as a function of the distance r from the center of the sphere?
6.
In a solid sphere of charge the
electric field grows linearly with distance. Inside the charged spherical shell
at right (r<a) what does the electric field do?
![Picture](/uploads/2/2/1/7/22171856/9624751_orig.png)
A. Constant and Zero
B. Constant but Non-Zero
C. Still grows linearly
D. Some other functional form (use Gauss ‘Law)
E. Can’t determine with Gauss Law
7. Above an infinitely large plane carrying charge density σ, the electric field points upwards and is equal to σ/2εo. What is the magnitude and direction of the electric field below the plane?
A. σ/2εo, down
B. σ/2εo, up
C. σ/εo, down
D. σ/εo, up
E. zero
8. A surface is so constructed that, at all points on the surface, the electric field vector points inward. Therefore, it can be said that
A. The surface encloses a net positive charge.
B. The surface encloses a net negative charge.
C. The surface encloses no net charge.
9. Experimenter A uses a very small test charge qo, and experimenter B uses a test charge 2qo to measure an electric field produced by two parallel plates. A finds a field that is
A. greater than the field found by B
B. the same as the field found by B
C. less than the field found by B
D. either greater or less than the field found by B, depending on the accelerations of the test charges
E. either greater or less than the field found by B, depending on the masses of the test charges
10. A thin semicircular conductor of radius R holds charge +Q. What is the magnitude and direction of the electric field at the center of the circle?
B. Constant but Non-Zero
C. Still grows linearly
D. Some other functional form (use Gauss ‘Law)
E. Can’t determine with Gauss Law
7. Above an infinitely large plane carrying charge density σ, the electric field points upwards and is equal to σ/2εo. What is the magnitude and direction of the electric field below the plane?
A. σ/2εo, down
B. σ/2εo, up
C. σ/εo, down
D. σ/εo, up
E. zero
8. A surface is so constructed that, at all points on the surface, the electric field vector points inward. Therefore, it can be said that
A. The surface encloses a net positive charge.
B. The surface encloses a net negative charge.
C. The surface encloses no net charge.
9. Experimenter A uses a very small test charge qo, and experimenter B uses a test charge 2qo to measure an electric field produced by two parallel plates. A finds a field that is
A. greater than the field found by B
B. the same as the field found by B
C. less than the field found by B
D. either greater or less than the field found by B, depending on the accelerations of the test charges
E. either greater or less than the field found by B, depending on the masses of the test charges
10. A thin semicircular conductor of radius R holds charge +Q. What is the magnitude and direction of the electric field at the center of the circle?