The diagram above shows some of the equipotential lines in plane perpendicular to two parallel charged metal cylinders. The potential of each line is labeled. The left cylinder is charged positively. What is the sign of the charge on the other cylinder? On the diagram above, sketch lines to describe the electric field produced by the charged cylinders. (We haven't done this yet. Here are two hints: You should be able to do this just by knowing the charge of the objects Electric field lines are always perpendicular to equipotential lines. Determine the potential difference, VA = VB,. between points A and B. How much work is done by the field if a charge of 0 50 coulomb is moved along a path from point A to point E and then to point D?
Explanation / Answer
a) The sign of the charge on the other cylinder is negative. c) The potential difference is VA - VB = -20 V + 12 V =-8.0 V d) The work done is W = qV =(0.50 V)(-8.0 V) = -4.0 V