The net magnetic moment of the system of magnetic poles shown in figure. is `ma` where n is nearly:

Answer

`(2)`

Explanation

The arrangement of magnetic poles as shown in figure is equivalent to two magnets of magnetic moments `M_1=M_2=(mxxa)` inclined to each other at `60^@`, figure.

`:.` Net magnetic moment is
`M=sqrt(M_1^2+M_2^2+2M_1M_2cos 60^@)`
`=sqrt((ma)^2+(ma)^2+2(ma)(ma)1/2)`
`M=masqrt3=1*732(ma)`,
which can be taken as `2(ma)`