Download Take Home Quiz

Physics 42 Take Home Quiz #4 Due 9/17
Print Name: _______________________ Lab 1 2 3 4
20 points
1. A thin insulating rod of length L has a total charge
Q and linear charge density: λ = λ0 x .
(a) Find λ0 .
(b) Derive an expression for the electric potential at the point (0,a).
Justify your work with pictures and words! Set up the integral and
solve it. Simplify all algebra. Your answers should be in
terms of L, a, Q and k only. Show how the units work out.
a
L
3. Show all your work, clearly label and justify anything you need to label or justify. Box answers.
A solid insulating sphere of radius a carries a net positive charge 3Q ,
uniformly distributed throughout its volume. Concentric with this sphere
is a conducting spherical shell with inner radius b and outer radius c, and
having a net charge –Q , as shown. Take the ground to be at infinity.
Using Gauss’s Law, find a general expression for the electric field in
terms of the radial distance from the center, r, for the following:
a) r < a
b) a < r < c
c) b < r < c
d) r > c
Find the potential, for the following,
d) r = 0
e) r = a
f) r = c
=
Q 3.00
=
nC , a 0.10
=
m, b 0.19
=
m, c 0.20m
using the values: