A very long magnet is held vertically with its south pole on a table. A single neutral point is located on the table to the

Options

A. 9 A- m
B. 6.75 A-m
C. 27 A-m
D. 1.35 A-m

Answer

D

Explanation

`OP= sqrt(225- 25) = sqrt200`
`B_(H)= (mu_(0))/(4pi) (M)/((OP^(2) + AO^(2))^(3//2))`
`rArr M= (0.4 xx 10^(-4))/(10^(-7)) xx (225 xx 10^(-4))^(3//2)`
`rArr M= 1.35 A m`