PES 1120 General Physics II
Practice Exam 3
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One (3” x 5”) index card may be used for formulas or other notes or diagrams.
Definitions & Concepts
1. Magnetic force on an electron traveling through a uniform magnetic field, B, as
shown in the given diagram. What direction is the electron traveling?
a.
b.
c.
d.
B
F
Up
Right
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Out of page
2. What units result from multiplying ohms and farads?
3. What is the value of the line integral ∮ ⃗ ⃗⃗⃗⃗ about the Amperian
loop shown?
Applications
4. Determine the voltage and current for the 8 resistor.
5. A capacitor of capacitance 12F and a resistor of 50  and a switch are connected in series with a
battery of voltage 10V. How long after the switch is closed does it take for the charge in the
capacitor to reach half of its maximum amount?
R. Gist
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Long Semester Ver. A, Rev 3
PES 1120 General Physics II
Practice Exam 3
6. A charged particle (charge = 5.0 µC) moves in a region of a 9 mT magnetic field directed along the
vector (2/3 i +1/3 j – 2/3 k). The particle’s velocity is specified by (3000 m/s)i + (4000 m/s)j.
What is the magnetic force vector on the particle?
7. A straight wire carries a current of 40 A in the region of a uniform magnetic field that is oriented
perpendicular to the wire. If the force per unit length on this wire is 2.0 N/m, determine the
magnitude of the magnetic field.
8. The figure shows the orientation of a rectangular coil consisting of 80 closely
wrapped loops or turns each carrying a current of 8.0 A. The magnetic field in
the region is 50 mT along the x-axis. The coil is hinged so that it can turn about
the y axis. If  = 30, a = 0.40 m, and b = 0.30 m, what is the magnitude of the
torque exerted on the coil?
9. What will be the radius of curvature (cyclotron radius) of the path of a proton (mass=1.67 x 10-27
kg, charge=1.602 x 10-19 C) with a kinetic energy of 3.0-keV (1eV=1.602 x 10-19 J) in a
perpendicular magnetic field of magnitude 0.40 T?
10. Two long parallel wires are separated by 4.0 cm. One of the wires carries a current of 20 A and
the other carries a 30 A current in the same direction. Determine the magnetic force per unit
length experienced by the wire carrying the greater current.
11. A long solenoid is wound with 960 turns per meter of thin wire through which a current of 300 mA
is maintained. What is the magnetic field strength at the center of the solenoid?
R. Gist
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Long Semester Ver. A, Rev 3