A magnet of length `14 cm` and magnetic moment `mu` is broken into two parts of length 6 cm and 8 cm. They are put at right angles to each other with the opposite poles togather. The magnetic dipole moment of the combination is:

Options

A. `mu//1.4`
B. `mu`
C. `1.4 mu`
D. `2.8 mu`

Answer

A

Explanation

The pole strength remains unchanged but distance between the poles becomes `=sqrt(8^(2)+6^(2))=10 cm`, so magnetic dipole moment of the combination.
`mu^(')=mxx10=mxx14/14xx10`
`=(mxx14)/1.4=mu/1.4`