mid1_practice_from_spring2010

mid1_practice_from_spring2010 - UIC Physics 142 Spring 2010...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
UIC Physics 142 Spring 2010 Midterm Exam I Page 1 of 7 Name: __________________________ Physics 142 Midterm 1 Practice Exam PROBLEM POINTS SCORE 1 20 2 23 3 20 4 20 5 17 Total 100
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UIC Physics 142 Spring 2010 Midterm Exam I Page 2 of 7 Name: __________________________ 1. (20 points.) In the figure shown, two point charges, q 1 and q 2 , have the same size, . These two charges, along with an as-yet unknown charge q 3 , are placed so as to form an equilateral triangle (shown with solid lines) with sides of length d = 4 mm. The point P is at the exact center of the triangle, so that it is an equal dis- tance, r , from each of the three charges. a) Find the distance r from each of the charges to point P . (3 pts.) b) Assume that q 1 = q 2 . i) Find by direct calculation (that is, don’t use symmetry or other arguments) the value of q 3 , if any, that causes the net electric field to be zero, E = 0, at point P. (6 pts.) c) Assume that - q 1 = q 2 . i) Find by direct calculation (that is, don’t use symmetry or other arguments) the value of q 3 , if any, that causes the net electric field to be zero, E = 0, at point P. (5 pts.) ii) If q 1 = q 3 , find the net electric field vector, , at point P expressed in components. (6 pts.) q 1 = q 2 = + 5.0 10 9 C E 20 d q P
Background image of page 2
UIC Physics 142 Spring 2010 Midterm Exam I Page 3 of 7 Name: __________________________ 2. (23 pts) An insulating sphere of radius 0.5R, with uniform charge density with net charge -q is suspended inside a conducting spherical shell with inner and outer radii of R and 1.5R.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

mid1_practice_from_spring2010 - UIC Physics 142 Spring 2010...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online