Question

Two identical bar magnets each of dipole moment $p_m$ and length l are perpendicular to each other as shown in the figure. The dipole moment of the combination is

• A. $2\,p_m$
• B. $\sqrt{2}\,p_m$
• C. $\frac{p_m}{\sqrt{2}}$
• D. $\frac{p_m}{2}$

Answer 1

Answer: (B)

$\sqrt{2}\,p_m$

Answer 2

Distance between the free north and south poles is $\sqrt{2} L$. Hence dipole moment of the combination is $\sqrt{2} p_m$