Question

In a rectangular loop in a uniform magnetic field, the sides BC and AD are perpendicular to \[\vec{B}\]. The magnitude of the force on each of these sides is:

Options

• \[F_1 = BIl\] and \[F_2 = BIl\]

• \[F_1 = 0\] and \[F_2 = 0\]

• \[F_1 = BIA\] and \[F_2 = BIA\]

• \[F_1 = BIb\] and \[F_2 = BIb\]

Answer 1

The sides BC and AD, each of breadth b, are perpendicular to \[\vec{B}\], so each experiences a force \[F = BIb\]. These two equal and opposite forces form the couple responsible for the torque on the loop.