Question

A long, straight wire carries a current along the z-axis, One can find two points in the x−y plane such that
(a) the magnetic fields are equal
(b) the directions of the magnetic fields are the same
(c) the magnitudes of the magnetic fields are equal
(d) the field at one point is opposite to that at the other point.

Answer 1

A long, straight wire carries a current along the z-axis, One can find two points in the x−y plane such that

(b) the directions of the magnetic fields are the same (c) the magnitudes of the magnetic fields are equal

(d) the field at one point is opposite to that at the other point.

Therefore the correct answer is Option (b) ,(c) and (d)

Explanation:

• If there is a live wire along the Z axis, the magnetic field can be adjusted using the right thumb line. Here, X means that the field is entered and O means that the field is output.
• If in the first case there are two points on the XY plane above the wire and at the same distance from the Z axis, then both are in the area X (input field), i.e. Y. In the same direction and size of the magnetic field. Having a magnetic field would be the same.
• In the second case, the direction of the electric field of both points would be opposite if two points in the XY plane were equidistant from the Z axis, but one point above the wire and the other below it. One point with the X direction (inward) and the other with the O direction (outward). In the first two cases, options (B), (C) and (D) are met. So options (B), (C) and (D) are appropriate.