A long bar magnet of time period T is cut in to four equal parts by cutting it perpendicular to both length and breadth. The time period of each part is

Time period of oscillation of magnetic needle isT=2πIMBAfter cutting mass and magnetic dipoloe moment becomes 14 and length and breadth becomes 12   Initially , I for a bar magnet is I=ml2+b212Finally , I2=m16l2+b212=I116   Initially, T1=T ,  I1=I  , M1=MFinally , T2=? ,  I2=I16 ,  M2=M4 We know , Time Period of oscillation = T=2πIMB∴ T1T2=I1I2×M2M1 ⇒TT2=I×16I×M4M=2 ⇒T2=T2