Question

The figure shows certain wire segments joined together to form a coplanar loop. The loop is placed in a perpendicular magnetic field in the direction going into the plane of the figure. The magnitude of the field increases with time. $I_1$ and $I_2$ are the currents in the segments $ab$ and $cd$. Then:

• A. $I_1>I_2$
• B. $I_1<I_2$
• C. $I_1$ is in the direction ba and $I_2$ is in the direction cd
• D. $I_1$ is in the direction ab and $I_2$ is in the direction dc

Answer 1

Answer: (D)

$I_1$ is in the direction ab and $I_2$ is in the direction dc

According to Lenz's law, current will be in anticlockwise sense as magnetic field is increasing into the plane of paper.
The induced magnetic field has to be out of the plane of the paper.
Hence, the current in the segment $ab$ will be from $a$ to $b$ and current in the segment $cd$ will be $d$ to $c$.