A long straight wire and a square loop of wire (both made of copper) sit in the
ID: 2018839 • Letter: A
Question
A long straight wire and a square loop of wire (both made of copper) sit in the plane of this screen. For several minutes there has been no current flowing in any wire. A battery (not shown) is connected and a current starts to flow to the left through the long straight wire. How does the current flow in the square loop?
A.) The loop is a short circuit, so no current flows in the loop.
B.) Because of induction, the current in the loop is proportional to the current in the straight wire.
C.) When the current in the straight wire is increasing, the current in the loop flows clockwise, but only as long as the current in the straight wire is increasing.
D.) The current in the loop flows counter-clockwise, but only as long as the current in the straight wire is increasing.
Explanation / Answer
When current starts to flow to the left through the long straight wire,then the inducedemf in the loop acts out of page, and magnetic flux acts in phase ( from Lenz's law)
hence, When the current in the straight wire is increasing, the current in the loop flows
clockwise, but only as long as the current in the straight wire is increasing.