A bar magnet with a magnetic moment 5.0 Am 2 is placed in parallel position relative to a magnetic field of 0.4 T. The amount of required work done in turning the magnet from parallel to antiparallel position relative to the field direction is

Question

A bar magnet with a magnetic moment 5.0 Am 2 is placed in parallel position relative to a magnetic field of 0.4 T. The amount of required work done in turning the magnet from parallel to antiparallel position relative to the field direction is (A) 4 J (B) 1 J (C) 2 J (D) ZeIO

Tardigrade Admin · Accepted Answer

u=-M B cos θ W=Δ u W=-M B cos 180°(-m B cos 0°) W=2 M B=2 × 5 × 0.4=4 J

Q. A bar magnet with a magnetic moment $5.0 A m^{2}$ is placed in parallel position relative to a magnetic field of $0.4 T$ . The amount of required work done in turning the magnet from parallel to antiparallel position relative to the field direction is

$4 J$

$1 J$

$2 J$

ZeIO

$u = - MB cos θ$
$W = Δ u$
$W = - MB cos 18 0^{\circ} (- m B cos 0^{\circ})$
$W = 2 MB = 2 \times 5 \times 0.4 = 4 J$

Q. A bar magnet with a magnetic moment 5.0Am2 is placed in parallel position relative to a magnetic field of 0.4T. The amount of required work done in turning the magnet from parallel to antiparallel position relative to the field direction is

4J

1J

2J