Question

tell the answer with correct explantion
plsss

Answer 1

A straight line and a point constitute an unique plane. This is true for all points in three dimensional

rectangular space (x,y,z). For convenience, let us consider that the point of observation (P) lies in xy plane

as shown in the gure below. We can say that the straight wire along y-axis also lie in xy plane. Clearly, this

plane is the plane of current length element dl and displacement vector r, which appear in the Biot-Savart

expression. The direction of magnetic eld is vector cross product dlX r, which is clearly perpendicular

to the plane xy. This means that the magnetic eld is along z-axis. This conclusion is independent of the

relative positions of current length elements of the wire with respect to observation point P.

In a nutshell, we conclude that the directions of magnetic elds due to all current elements constituting

straight wire at a point P are same. Though, magnitudes of magnetic elds are dierent as dierent current

elements are located at dierent linear distance from the point i.e. displacement vectors (r) are dierent for

dierent current length elements (dl).

the answer is outside the page

Answer 2

current is following in direction Y to X

using right hand thumb rule , thumb in the direction of current and reamaing fingers turned shows field

here it is into the paper at A