Transcript lec30

A charge distribution lies along a segment of the
positive x axis. On that segment, the linear
charge density l is b where b is a constant
x
having units of Coulombs. What is the charge
on an infinitesimal length dx' of the charged
segment?
a) b dx
x
b) q dx'
c) l
d) b
e) b dx'
kq
In Coulomb's Law for the Electric Field, E  2

what does the r stand for?
a) Radius
b) The separation of the charged particle
and the point in space at which the
electric field is being calculated.
c) The separation of the two charged
particles.
d) None of the above.
Three charged particles lie on the x axis: one at the
origin, one to the left of the origin (that is, at a position
having a negative x value), and another to the left of
that one. A person is asked to determine the electric
field due to the trio, at a point on the positive y axis.
The person determines the distance r that each
particle is from the point on the y axis in question and
kq
then calculates the value of E  2 for each of the

three particles in turn. Then the person adds the
three values thus determined and gives the sum as
the total electric field at the point on the y axis in
question. Is this procedure correct?
a) Yes.
b) No.
In calculating the electric field due to a charged
line segment, one considers each bit of the line
segment to be a point charge.
a) True.
b) False.