A long curved conductor carries a current I(I is a vector ). A small current element of length dl, on the wire induces a magnetic field at a point, away from the current element and the point is r, making an angle with current element then, the induced magnetic field density, dB(vector) at the point is (`mu_(0)`=Permeability of free space)

Options

A. `(mu_(0)Idlxxr)/(-4pir)`(Perpendicular to the current element dl)
B. `(mu_(0)Ixxrxxdl)/(4pir^(2))` (Perpendicular to the current element dl)
C. `(mu_(0)Ixxdl)/(r)` (Perpendicular to the plane containing the current element and position vector r)
D. `(mu_(0)Ixxdl)/(4pir^(2))` (Perpendicular to the plane containing current element and position vector r)

Answer

B

Explanation

The induced magnetic field dencity,
`db=(muIxxrxxdl)/(4pi^(2)`