The pole strength of a horse shoe magnet is 90   A   m and distance between the poles is 6   cm . The magnetic induction at mid point of the line joining the poles is,

Step-by-step solution

Magnetic induction B due to a monopole is given by B   =   μ 0 4 π m r 2   μ 0   =   a b s o l u t e   p e r m e a b i l i t y   o f   t h e   m e d i u m ,   m   =   p o l e   s t r e n g t h ,   r   =   d i s tan c e   o f   t h e   p o i n t   f r o m   p o l e   w h e r e   B   i s   t o   b e   c a l c u l a t e d Magnetic induction due to both the poles at the m