Goal: Link work and potential
Source: 283-465 Interpreting voltage
The potential at two points in space is: V1=200 Volts,
V2=300 Volts. Which of the following statements is true for
moving a point charge, q, from point 1 to 2?
- The work done by an external agent to
move q from point 1 to 2 is positive.
- Can’t determine the work
done because you don’t know the direction of V at the two points.
- The work done by the electrical force exerted on q in moving it from
point 1 to 2 is: W = -q(100 Volts).
- A and B
- A and C
- A, B, and C
- None of the above
(3) is the best response. Statement A is true only if the charge
is positive. The important thing is to see if students correctly
envision the electric field lines as directed from higher potential to
Any response involving statement B should be discussed thoroughly as it
indicates confusion between fields and potentials.