Two bar magnet having magnetic dipole moments 4 A-m2 and 5 A-m2 are kept as shown below. The resultant dipole moment will be

Question

Two bar magnet having magnetic dipole moments 4 A-m2 and 5 A-m2 are kept as shown below. The resultant dipole moment will be (A) √21 A m2 (B) √41 A m2 (C) √61 A-m2 (D) √31 A-m2

Tardigrade Admin · Accepted Answer

Here, M1=4 A-m2 M2=5 A-m2 <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/6b5c446c488a1def1970ee587b5f540f-.png" /> According to parallelogram law of vector addition, resultant dipole moment M M =√M12+M22+2 M1 M2 cos 60° =√42+52+2 × 4 × 5 × cos 60°=√61 A-m2

Q. Two bar magnet having magnetic dipole moments $4 A - m^{2}$ and $5 A - m^{2}$ are kept as shown below. The resultant dipole moment will be

$21 A m^{2}$

$41 A m^{2}$

$61 A - m^{2}$

$31 A - m^{2}$

Here,
$& M_{1} = 4 A - m^{2}$
$M_{2} = 5 A - m^{2}$

According to parallelogram law of vector addition, resultant dipole moment $M$
$M = M_{1}^{2} + M_{2}^{2} + 2 M_{1} M_{2} cos 6 0^{\circ}$
$= 4^{2} + 5^{2} + 2 \times 4 \times 5 \times cos 6 0^{\circ} = 61 A - m^{2}$

Q. Two bar magnet having magnetic dipole moments 4A−m2 and 5A−m2 are kept as shown below. The resultant dipole moment will be

21​Am2

41​Am2

61​A−m2

31​A−m2