96 Week 2: Continuous Charge and Gauss’s Law
after doing it.
Problem 3.
θ 0λ 0RAn arc of linear charge densityλ 0 and radiusais centered on the origin and subtends an angle
θ 0 as shown. Find the electric field at the origin.
Problem 4.
A point dipole~pis located a distancerfrom an infinitely long line of charge with a uniform
linear charge density +λ 0. Assume that the dipole is aligned with the field produced by the line
charge. Determine the force acting on the dipole. Is it attracted to or repelled by the line?
Note that you may want to look back at some of your homework problems from last week as you
do this. Which ones are likely to help you out? How do we make a “point dipole”?