Examen Final De Fisica

PHYSICS 211
Final EXAM FALL 2008-09

TIME: 120 minutes
January 27, 2009


DO NOT OPEN THIS EXAM BEFORE YOU ARE TOLD TO BEGINNAME________________________________________________
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Useful information

ε0=8.85x10-12 C2/N.m2.
μ0=4p x 10-7 Tm/A.
q = 1.6 ( 10(19 C
me= 9.1x10-31 kg. mp= 1.67×10-27 kg.
ke=8.9875x109 Nm2/C2The solution for the differential equation of the form

dy/dt + ay = b is y=(b/a)(1-exp(-at))




Grading

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Part A: Multiplechoice questions (20) each question has 2 points

1. If a = 3.0 mm, b = 4.0 mm, Q1 = 60 nC, Q2 = –80 nC, and q = 36 nC in the figure, what is the magnitude of the total electric force on q?[pic]
a. 5.0 N
b. 4.4 N
c. 3.8 N
d. 5.7 N
e. 0.60 N




2. A positive point charge q is placed off center inside an uncharged metal sphere insulated from theground as shown. Where is the induced charge density greatest in magnitude and what is its sign?

[pic]
a. A; negative.
b. A; positive.
c. B; negative.
d. B;positive.
e. C; negative.




3. The electric potential inside a charged solid spherical conductor in equilibrium

a. is always zero.
b. is constant and equal to its value at thesurface.
c. decreases from its value at the surface to a value of zero at the center.
d. increases from its value at the surface to a value at the center that is a multiple of the...