Two identical magnets are placed perpendicular to each other with their unlike poles in contact. If each magnet has a magnetic moment 'M', what is the magnetic moment of the combination?

Explanation

Magnetic moment is a vector
It acts along South to North .
The resultant of two perpendicular vectors is obtained by using parallelogram law of vectors .
Here `M_1 = M_2 = M `
`:.` New magnetic moment
` = sqrt( M^(2) + M^(2) + 2M. M cos theta ) = sqrt( M^(2) + M^(2) + 0)`
New magnetic moment = ` sqrt(2) M`