Two similar bar magnets P and Q each of magnetic moment M, are taken,. If P is cut along its axial line and Q is cut along its equatorial line, all the four pieces obtained have

Options

A. Equal pole strength
B. Magnetic moment `M/4`
C. Magnetic moment `M/2`
D. Magnetic moment `M`

Answer

C

Explanation

If pole strength, magnetic moment and length of each part are `m^('),M^(')` and `L^(')` respectively then

`(m^('))_(P)=m/2 , (m^('))_(Q)=m`
`(L^('))_(P)=L , (L^('))_(Q)=L/2`
`implies (m^('))_(P)=M/2 implies(M^('))_(Q)=M/2`