Question

Two circular loops lie side by side in the same plane. One is connected to a source that supplies an increasing current, the other is a simple closed ring. Is the induced current in the ring is in the same direction as that in the loop connected to the source or opposite? What if the current in the first loop is decreasing?

Answer 1

The induced current direction in the ring as that in the loop:

• According to Lenz' s law, an induced current creates a magnetic field that opposes any change in the magnetic flux of the ring.

• When the current is increasing in one loop (A), it creates a magnetic flux which goes through the other loop (B). As per Lenz's Law, induced current in B must oppose the magnetic flux of A. If magnetic flux is coming out of the page in A, it is going into the page at loop B. To oppose this, magnetic flux should be induced which comes out of the page. So, current should be in same direction in B as that of A.
• But if the current in the loop was decreasing, the currents would be in opposite directions.