Question

An electric current through a metallic conductor produces………… around it
A. Magnetic field
B. Mechanical force
C. Induced current
D. None

Answer 1

Hint: The charge flowing through a conductor is basically the reason for electric current. The current carrying conductor will be having a magnetic field around it. Stationery charges cannot produce a magnetic field. The charges should be in motion.

Complete step by step answer:
 It is already known that the stationary charges can develop an electric field around it proportional to the magnitude of the charge. The similar way of approach has been taken here. The moving charges can create magnetic fields around the conductor proportional to the current and hence a current carrying conductor is able to produce a magnetic effect around it. This magnetic field is due to the subatomic particles in a conductor. A magnetic field is a vector quantity having both magnitude and direction. Magnetic field due to a conductor carrying current actually depends on the current travelling through the conductor and distance of the position from the conductor. The direction of the magnetic field is normal to the conductor. If we wrap our fingers of the right hand around the conductor with our thumb pointing in the direction of the current, then the direction in which the fingers curl around will give the direction of the magnetic field. Therefore an electric through a metallic conductor produces a magnetic field around it. Hence the correct answer is option A.

Note:
The magnetic field developed due to a current carrying conductor is having a lot of peculiarities. The magnetic field is encircling the conductor. The field lines will be in a plane perpendicular to the conductor. And the reversal of current direction reverses the direction of the field.