Q. In which orientation the resultant magnetic moment of two magnets, will be zero, if magnetic moment of each magnets is $M$ in the following figures?
A) [image:4_image40.emf]
B) [image:4_image41.emf]
C) [image:4_image42.emf]
D) [image:4_image43.emf]
Explanation
(b) $M^{'} = \sqrt{M^{2} + M^{2}} = \sqrt{2}M$. As magnetic moments are in a closed loop in Fig. (b)
$\therefore M = 0$
In Fig. (c) ${\ M}^{'} = M - M = 0$
In Fig. (d)
$M^{'} = \sqrt{M^{2} + M^{2} + 2MM\ cos60{^\circ}} = \sqrt{3}M$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.