A long magnetic needle of length21, magnetic moment M and pole strength m is devided along its axis into two parts of equal lengths. The magnetic moment and polestrength of each half will be

Options

A. `(M)/(2) & (m)/(2)`
B. `M & (m)/(2)`
C. `(M)/(2) & m`
D. `M & m`

Answer

C

Explanation

When the length of is halved, pole strength remain same. Magnetic moment will be reduced to half when the length of magnet is halved.