Question

Can you explain how to determine the direction of current in the transformers when we change the loop?

Answer 1

The induced current will be counterclockwise (ccw). As the bar moves upward through the constant magnetic field region, the area of ​​the loop decreases, so the flux through the loop decreases. By Lenz's law, any induced current will tend to oppose the decrease.

You can find it by pointing your right thumb in the direction of the current in the wire and curling your fingers. Your fingers will be curled in the same direction as the magnetic field around the wire.