A2L Item 150

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?

  1. The work done by an external agent to
    move q from point 1 to 2 is positive.
  2. Can’t determine the work
    done because you don’t know the direction of V at the two points.
  3. The work done by the electrical force exerted on q in moving it from
    point 1 to 2 is: W = -q(100 Volts).
  1. A
  2. B
  3. C
  4. A and B
  5. A and C
  6. A, B, and C
  7. 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.