AP EAMCET Engineering 23 Sep 2020 Shift 1 Paper

The magnetic dipole moment of a magnetic dipole is given by
M=m×L...(i)
where, m is pole strength and L is dipole length.
According to question,Now, rod is bent in form of a semi-circular arc,M′=m×(2R)
=m×2×(‌

L

π

)[∵πR=L or R=‌

L

π

]
=‌

2

π

(mL)
M′=‌

2

π

M  [ from Eq. (i)]