PES 1120 General Physics II
Practice Exam 1
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One (4” x 6”) index card may be used for formulas or other notes or diagrams.
Definitions & Concepts (2 pts each)
1. (2 pts) Which of the following illustrates electric field lines between two point charges of
equal but opposite charge (dipole)?
2. What units will result from the multiplication of electric field units times charge units?
a. Newtons per coulomb
b. Coulombs per second
c. Newtons
d. Coulombs
3. A negative charge is brought from very far away until it is near a positively charged sphere.
Which of the following is true?
a. Work is done by the system (potential drops)
b. Work is against the system (potential rises)
c. No work is done
4. Equipotential lines can cross each other.
a. True
b. False
Applications (4-6 pts each)
5. If a = 3.0 mm, b = 4.0 mm, Q1 = –60 nC, Q2 = 80 nC, and q = 30 nC in the figure, what is the
magnitude of the total electric force on q?
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Short Semester Ver. A, Rev 1
PES 1120 General Physics II
Practice Exam 1
6. If a = 60 cm, b = 80 cm, Q = –6.0 nC, and q = 6.0 nC, what is the electric field vector at point
P in the figure?
7. An electron enters a region of uniform electric field (E = 50 N/C) with an initial velocity of 40
km/s directed the same as the electric field. What is the speed of the electron 1.5 ns after
entering this region?
8. 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.
9. A uniform electric field of strength 10 N/C is pointing in the direction defined by
u=0.8j + 0.6k. What is the electric flux due to this field that passes through a square of side
length 1 cm that is lying in the x-y plane? (Assume the face of the square in the +z direction to
be the front.)
10. An ion has a net charge of -6.41 x 10-19 C. What is the difference between the number of
protons and electrons for this ion? Are there more electrons or more protons? (Fundamental
quantum of charge is e = 1.602 x 10-19 C.)
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Short Semester Ver. A, Rev 1
PES 1120 General Physics II
Practice Exam 1
11. Charge of a uniform density (8.0 nC/m2) is distributed over the entire xy plane. A point charge
of 5.0 nC is fixed at z = 1.0 m. Determine the magnitude of the electric field at the point b,
which is exactly halfway between the plane and the point charge.
12. Two particles, one of charge +4 pC and the other of -2 pC are placed 1 cm apart.
a. How much energy was involved in constructing this configuration?
b. What is the potential at a point 1 cm equidistant from both charges?
13. A conducting sphere of 0.1 m radius has 1 nC of charge placed on it. What is the voltage at a
point 0.2 m from the surface of the sphere if voltage at infinity is taken to be zero?
Types of charged objects that may be used on this exam:
Point charge, Sphere charge (outside), Infinite line charge, Infinite plane charge
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Short Semester Ver. A, Rev 1