A current passes through a wire from south to north. What will be the direction of the magnetic field at any point vertially above the wire
Answers
Answer:
Explanation:
A current in a straight wire sets up a magnetic field such that the lines of force are circular and concentric with the wire as axis. The direction of the field is given by the right hand thumb rule described in the other answers. In other words, the tangent to the lines of force, and hence the direction of the field is always perpendicular to the axis of the wire. The magnet thus finds itself in two perpendicular magnetic fields, the horizontal component H of the Earth's field from South to North, and the field F due to the current from West to East.
If the magnet is free to rotate in the horizontal plane, it will rotate clockwise till it makes an angle theta with H, such that F = H tan theta
If the current is very large, then F >> H and the magnet will be almost perpendicular to the North - South direction