Q. A long magnetic needle of length $2L$, magnetic moment $M$ and pole strength $m$ units is broken into two pieces at the middle. The magnetic moment and pole strength of each piece will be
A) $\frac{M}{2},\frac{m}{2}$
B) $M,\frac{m}{2}$
C) $\frac{M}{2},m$
D) $M,\ m$
Explanation
(c) Pole strength of each part $= m$
Magnetic moment of each part
$= M^{'} = m^{'}L^{'} = mL = \frac{M}{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.