A2L Item 234

Goal: Reason regarding forces between current elements

Source: 283-660 Force between two wires

A very long wire lies in a plane with a short wire segment. The long
wire carries current I, while the short wire of length L carries current
i. The two wires are parallel to each other. Which of the following
statements are true?

  1. The direction of the magnetic force
    exerted by the long wire on the short wire is directed away from the
    long wire.
  2. The magnitude of the force on the short wire is
  3. The long wire experiences a force
    of exactly the same magnitude as the force experienced by the short
  1. A only
  2. B only
  3. C only
  4. A and B
  5. A and C
  6. B and C
  7. A, B, and C
  8. None of them are true



(6) The force is attractive between the wires so statement A is false.
Students need to interpret the phrase ‘very long’ as implying that the
wire is infinite.