An infinitely long cylinder is kept parallel to an uniform magnetic field B directed along positive z-axis. The direction of induced current as seen from the z-axis will be

Options

A. zero
B. anticlockwise of the +ve z axis
C. clockwise of the +ve z axis
D. along the magnetic field

Answer

A

Explanation

For a current to induce in cylindrical conduction rod,
(a) the conducting rod should cut magnetic lines of force which will happen only when the conducting rod is moving, Since cnducting rod is at rest, no current will be induced.
(b) The magnitude/direction of the magnetic field changes. A changing magnetic field will create an electric field which can apply force on the free electrons of the conducting rod and a current will get induced.
But since the magnetic field is constant, no current will be induced.