A `25cm` long solenoid has radius `2cm` and `500` total number of turns. It carries as current of `15A`.If it is equivalent to a magnet of the same size and magnetization `bar(M)` (magnetic moment//volume) then `|bar(M)|` is:

Options

A. `30000 pi Am^(-1)`
B. `3pi Am^(-1)`
C. `30000 Am^(-1)`
D. `300 Am^(-1)`

Answer

c

Explanation

`vecM` (mag. Moment/volume)=`(NiA)/(Al)`
`=(Ni)/(l)=((500)15)/(25xx10^(-2))=30000Am^(-1)`