Question

Two identical thin bar magnets, each of length $L$ and pole strength $m$ are placed at right angles to each other, with the $N$-pole of one touching the south pole of the other. Find magnetic moment of the system.

• A. $2\sqrt{2}M$
• B. $\sqrt{3}M$
• C. $\sqrt{2}M$
• D. $\sqrt{5}M$

Answer 1

The correct option is C $\sqrt{2}M$

Given;

Pole strength = m

Length = L

$|therefore{N}_2{S}_1=\sqrt{N_1{S}_1^2+N_2{S}_2^2}=\sqrt{{2L}^2}=\sqrt{2L}$ and

magnetic moment $=m\times N_2{S}_1=\sqrt{2}mL=\sqrt{2}M$