A conducting sphere of radius 20 cm has a charge Q placed on it producing a field of magnitude
If the potential at the surface was
when the field was 
what is the potential when the field is 2
?
A.
B. 2
C. 4
D. 5
E. 16
B. 2
You might also like to view...
Suppose that a symmetry argument of some kind tells us that the electric field in a certain region points directly away from the nearest point on the y axis and has a magnitude that depends only on r, the distance to that nearest point. For which of the gaussian surfaces listed, would it be easiest to calculate the net flux of the electric field through that surface?
A. A cubical surface oriented so that two opposite faces are perpendicular to the y axis.
B. A spherical surface.
C. A cylindrical can-like surface oriented with its central axis perpendicular to the y axis.
D. A cylindrical can-like surface oriented with its central axis parallel to the y axis.
E. A cone-like surface oriented with its central axis parallel to the y axis.
Compared to natural background radiation, the amount of radiation received by U.S. citizens from normally operating nuclear power plants is
A) about 10% as much. B) very much less. C) roughly the same amount. D) absolutely zero. E) considerably more.
The zirconium nucleus contains 40 protons, and an electron is 1.0 nm from the nucleus. What is the electric force exerted on the electron by the nucleus? ( e = 1.60 × 10-19 C, k = 1/4??0 = 9.0 × 109 N ? m2/C2 )
A) 2.9 nN B) 1000 C C) 3.7 nN D) 6.8 nN E) 9.2 nN
Near the earth the intensity of radiation from the Sun is 1350 W/m2. What volume of space in this region contains 1.0 J of energy?
A) 4.5 × 10-6 m3 B) 3.3 × 102 m3 C) 7.4 × 10-4 m3 D) 1.4 × 103 m3 E) 2.2 × 105 m3