Concept explainers
The direction of induced current when the current in first ring is increasing and decreasing.
Answer to Problem 1CQ
The direction of induced current when the current in first ring is increasing is same as the first loop. When the current is decreasing, the induced current is opposite to that of the first loop.
Explanation of Solution
According to Lenz law, the direction of induced current is in such a way that it opposes the change that produces it. Initially, if it is assumed that the current in first loop is clockwise, then the direction of magnetic field into the plane of paper is leaving away. The magnetic field outside the first loop is pointed outside. In the second loop, the direction of field due to the induced current is into the paper. Therefore, to oppose the increasing flux, the direction of current in second loop must be same as the first loop.
When the current is decreasing, the magnetic flux is also decreasing in the direction outwards. Therefore, to oppose the change in magnetic flux, the induced current in the second loop is in the direction opposite to that of the first loop.
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