SP211
Worksheet 10
Electric potential and potential energy
Problem 1
A spherical shell of radius R has a total charge +Q uniformly distributed on its surface. Find the electric
SP 212 Worksheet
potential distance at distances (a) r = 0, (b) r = R/2, (c) r = R, (d) r = 2R. You should set the potential
Lesson
10:farCh.
24.6-24.8,
Electric
to
be zero very
from the
center, i.e. V (∞)
= 0 Drawpotential
a graph of theenergy
electric potential as a function of r.
HINT: Remember what the electric field due
R f to a spherical shell is both outside and inside the shell.
~ · d~r and choosing your initial point to be at distance r from
You can find the potential using Vf − Vi = i E
1)
A
spherical
shell
of
radius
R
has
a uniformly distributed excess charge of +Q.
the center and your final point out at infinity.
Find
at distances (a) r = 0, (b) r = R/2, (c) r = R, and (d) r = 2R from the center of the
of V vs.2r.
Problem
Repeat problem 1, but assume that there is an additional point charge −Q located at the center of the
sphere.
2) Repeat problem 1, but now assume that there is a point charge Q located
Problem 3
at the
3) Seven charged particles are fixed in place to form a square with an edge length o
distanc
Seven point charges are placed on the edges of a square of side length L as shown below. How much work
must we do to bring a particle of charge +2e initially at rest from an infinite
must be done to move a charge of size +2e initially from rest at an infinite distance away to the center of
square?
the
square.