JEE Main & Advanced
Physics
Magnetism
Question Bank
Magnet and its Properties
question_answer
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 [NCERT 1983; DPMT 1987]
A) \[\frac{M}{2},\frac{m}{2}\]
B) \[M,\frac{m}{2}\]
C) \[\frac{M}{2},m\]
D) \[M,m\]
Correct Answer:
C
Solution :
Pole strength of each part =m Magnetic moment of each part \[={M}'={m}'{L}'=mL=\frac{M}{2}\]