Two magnets of magnetic moments `4Am^(2) and 3Am^(2)` are joined to form a cross `(+)`, then the magnetic moment of the combination is

Options

A. `4Am^(2)`
B. `1Am^(2)`
C. `7Am^(2)`
D. `5Am^(2)`

Answer

D

Explanation

Magnetic dipole moment is a vector quantity and they are at angle of `90^(@)`.
Thus they can be added as
perpendicular vectors
`M=sqrt(M_(1)^(2)+M_(2)^(2))`
`N=sqrt(3^(2)+4^(2))=5`