Question

The magnetic induction field $B$ around a current carrying straight conductor is

• A. Pependicular to the current.
• B. Parallel to the current.
• C. Opposite in direction to the current.
• D. None of the above.

Answer 1

The correct option is A Pependicular to the current.

The magnetic lines of force are concentric circles, with current carrying straight conductor at the centre and perpendicular to the plane of these concentric circles. The direction of the magnetic lines of force is clockwise or anticlockwise depending on the direction of flow of current. The direction of $B$ is obtained by drawing tangent to the concentric circles at any point on it. It is seen that different point on the concentric circle gives different directions of $B$ and $B$ is always perpendicular to the direction of current.