Two magnets each of magnetic moment ‘M’ are placed so as to form a cross at right angles to each other. Magnetic moment of the system will be

2M    $M\sqrt 2$ M/2    $M/\sqrt 2$

$M\sqrt 2$

The magnetic moment of each magnet is M i.e., M1 = M2 = M The two magnetic moments are perpendicular. Hence net magnetic moment            $M' = \sqrt {M_1^2 + M_2^2} = \sqrt {2M^2} = M\sqrt 2$