A2L Item 207
- Description: Compare work done on a charge as it moves along different paths in the presence of other fixed charges.
- Goal: Hone the conservative nature of the electrostatic field
- Source: 283-240 Work moving charge around
- Keywords: Electromagnetism, Work
The question for students:
Two point charges are fixed on the x-axis. A positive charge from point P to the origin along the different paths shown in the diagram below. For which path would you do the most work?
- Path A
- Path B
- Path C
- Path D
- Cannot be determined
- None of the above
Commentary for teachers:
Answer
(6) Relating the work done to the change in potential should be stressed. Once this point is made, a good follow-up question is to ask how much work would be done if one of the charges on the x-axis was negative.