Download Exam 3 Solutions - University of Utah Physics

Physics 2020 - Spring 201 5
Name:
Discussion TA:
EXAM 3
Dr . Mishchenko
Unid:
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Discussion Section:
1
[35pts.] A magnetic field has a magnitude of B, and an electric field has a magnitude of E. Both fields point in the same
direction. A positive q charge moves at a speed of v in a direction that is perpendicular to both fields.
(a)
(b)
Determine the magnitude of the net force that acts on the charge. Solve this problem in algebraic form (express
FNet in terms of B, E, q, and v).
Use the obtained formula to find numerical values for the maximum current if B = 1.3 x 10~3 T,
E = 3.8 x 103 N/C, q = 2.7 uC and v = 4.0 x 106 m/s.
Physics 2020 - Spring 2015
Dr . Mishchenko
EXAM 3
Unid:
Name:
Discussion TA:
Discussion Section:
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2
[45 pts.J A copper rod is sliding on two conducting rails that make an angle of 6 with respect to each other, as in the
drawing. The rod is moving to the right with a constant speed v. A uniform magnetic field B is perpendicular to the
plane of the paper.
(a)
(b)
Determine the magnitude and direction (clockwise or counterclockwise) of the average emf induced in the
triangle ABC during a time period At after the rod has passed point A. Solve this problem in algebraic form
(express in terms of 9, v, B, At}.
Use the obtained formula to find numerical values for emf if B = 0.63 T, 0 = 25 degrees, v = 0.9 m/s and
At = 5 sec, and give a written explanation for the direction of the current.
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Physics 2020 -Spring 2015
EXAMS
Dr . Mishchenko
Name:
Unid:
Discussion TA: /j ^^
Discussion Section:
3
[20 pis.] The drawing shows that a uniform magnetic field is directed perpendicularly out of the plane of the paper and
fills the entire region to the left of the y axis. There is no magnetic field to the right of the y axis. A rigid right triangle
ABC is made of copper wire. The triangle rotates clockwise about the origin at point C. What is the direction (clockwise
or counterclockwise) of the induced current when the triangle is crossing
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