Download Electric Fields and Electric Potential QQ

Questions on Electric Fields and Electric Potential
a. Compare the relative acceleration for a proton, neutron, and an electron, when placed in a
uniform electric field going to the right of the page.
b. How will the following changes effects two charged objects of charge Q how would bringing
them to a distance of half their original separation distance effect voltage and electric field?
c. What is the direction of an electric field at the surface of a conductor? Explain.
d. Draw the electric field and force vectors acting on each charge (you should show 8 vectors total
6 for force and 2 for electric field, do not show the electric field lines surrounding the particles).
Show appropriate magnitude and direction. Make sure
your vectors are of appropriate magnitude and
direction.
e. For each of the charged particle systems rank the three letters in order of
a. increasing magnitude electric field. (show vectors to
assist)
b. increasing electric potential
f.
A rod with a –charge is brought close to two conductive spheres that are touching. As the rod is
close the sphere on the right is moved away and then the rod is moved away. What will be the
relative charges on each sphere? Explain
g. Compare the magnitude of the electric field and electric potential for each at the dots on the
right. (assume the three variations are isolated from each other)
h. Draw electric field lines around the pairs of charges
a.
b.
i. For the two positive charges shown,
-Superimpose a graph of the electric potential
(voltage) as a function of distance in the x direction
-focus on locations d/2 from the charged particles
(note dashes below on x-axis)
j. Four particles are in electric fields created by large flat
sheets of charge. The particles do not have sufficient
charge to interfere with each other. The particles are designated, as shown,
A,B,C, and D.
A= Charge of 0, mass of 1
B=Charge of 1, mass of 2
C=charge of 1, mass of 1
D=charge of 2, mass of 2
Determine the following (with numerical relevance when compared to
particle C).
1.
2.
3.
4.
5.
l.
the relative acceleration of each particle
the kinetic energy of each particle when it hits the sheets
the work done by the electric field during the shift
the loss of electric potential
Speed at impact
In the following, you have a thick non-conducting spherical shell
where the charge is uniformly distributed throughout the interior.
Arrange the following letters in order of increasing_____________.
(note any equalities)
1. Electric field
2.
Electric potential
m. Where on the surface of a metal box with a positive charge have
the greatest________?
a. Electric field
(What is the best indicator of the electric field at the surface of a conductor?)
b.
Electric potential
n.
If a maximum exists, how could we find the maximum (or minimum) of a voltage function given as a function
of distance?
o.
Considering the potential diagram shown (with equipotential lines
given),
a. Where is the electric potential at a maximum (A-D)?
b. Where is the electric field at a maximum (A-D)?
c. Where could the electric field be zero?
p.
Compare the velocity magnitude of each particle (a and b) by the time they get to
from the current location across the length d. Assume the particles do not interact
with each other and they each start with the same magnitude velocity, V.
q.
Considering the following graphs of electric
fields and electric potentials, draw the opposing graph.
r.
Assume that each wire has an equal and opposite charge density per
unit length.
i. Give the electric field at point P (left, right, or zero) and explain
ii. Predict the electric potential at point P (negative, positive, or zero)
s.
If a proton could be released at the edge of the conducting sphere with 40V
and radius R,
i. How far would object be from the center of the sphere
when it is at the 20V equipotential?
ii. If the speed of the proton is S at this location,
approximently what will be the speed when the proton as
the distance away from the sphere approaches infinity
(Speed<2S, Speed=2S, Speed>2S)?
t.
We charge a sphere slowly building up to charge Q and W is the amount of
work required. How much additional work will be required to slowly add more charge until the sphere has
charge 2Q? (assume the charge composing Q is infintesimally small)
u.
A charged object has a spherical conductive shell placed around it. How does this change the electric field and
electric potential at point a and b?
v.
What is the relative net work required by an external force to assemble 3 charges of equal magnitude a
distance d from each other (in equilateral traingle formation)?
a. 3 positive charges
b.
2 positive and one negative charge
w. Give the electric field lines based on the equipotential lines, indicate the possible charges at
the missing centers.