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. M/10
B. M
C. M/1.4
D. 2.8 M

Answer

C

Explanation

Pole strength of the original magnet, `m=(M)/(14)`
Effective distance between the poles = AB
`=sqrt(6^(2)+8^(2))`
`=10 cm`
`therefore` Magnetic moment of the combination
`M'=m.2l=(M)/(14)xx10=(M)/(14)`