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

Answer

b

Explanation

`|vec M| ` (Magnetic Moment/volume) = `(NiA)/(Al) = (Ni)/l`
` = ((500)15)/(25 xx 10^(-2)) = 30000 Am^(-1)`
Hence option (b) is correct.