Question
Q8 As sketched in the diagram below, Wire 1 and Wire 3 are parallel and they carry equal currents out of the page (I1 and Is). Wire 2 is parallel to Wire 1 and Wire 3, and it carries an unknown current in an unknown direction. Wire 1 and Wire 3 have the same separation as Wire 3 and Wire 2. The vector force on Wire 3 is indicated on the sketch. What is the size and direction of the current in Wire 2, compared with the current in Wire 1? [Big hint: like currents attract, opposite currents repel...] a) same current as Wire 1; direction out of page b) double the current of Wire 1; direction out of page c) same current as Wire 1; direction into page d) double the current of Wire 1; direction into page e) square of the current of Wire 1; direction out of page
Explanation / Answer
answer (c).
wire 2 exerts same force as that of 1 on wire 3 but it repels hence direction is opposite.
