Q. A long magnet is cut into two equal parts, such that the length of each half is same as that of original magnet. If the period of original magnetic is T, the period of new magnet is
A) T
B) $\frac{T}{2}$
C) $\frac{T}{4}$
D) $2T$
Explanation
(a) Time period $T = 2\pi\sqrt{\frac{I}{MB_{H}}}$
As the magnet is cut into two equal parts along parts along axis, then for each part
$I^{'} = \frac{I}{2}$
$M^{'} = \frac{M}{2}$
$\therefore$ Time period of new magnet,
$T^{'} = \sqrt{\frac{I^{'}}{M'B}} = \sqrt{\frac{I \times 2}{2 \times M \times B}}$
$T’ = T\ $
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.