Question

When current flows through a wire, it creates ………… field around it. Fill in the blank:
(A) Gravitational
(B) Magnetic
(C) Repulsive
(D) Attractive

Answer 1

Hint: A gravitational field is existent in the presence of a massive body. The magnetic field exists in the presence of a charge moving with a particular velocity.

Complete step by step answer
In general, current is the rate of flow of charges usually through a conductor. Most of the time, the charges are electrons set in a directional motion due to an electric field or a potential difference applied across the ends of the conductor.
To know which field is created, let us investigate the two types of field given in the options (there are no such thing as a repulsive or attractive fields)
Gravitational field – the gravitational field is a kind of field which is generated solely due to the presence of a massive body such as planets, stars, asteroids and others. The gravitational force is always attractive, and thus cannot repel an object. This is because the gravitational field always acts radially inward towards the centre of the field
Magnetic field – the magnetic field is a field which is generated due to the movement (not solely the presence) of charge. When charges move they generate a magnetic field which circulates about themselves and the field lines parallel to one another
Hence, since current is the movement of charge, current generates a magnetic field.

Thus, the correct option is B.

Note
For clarity, although we said the gravitational field is generated by massive bodies such as planets and stars, note that this is not only true. The gravitational field can be generated by any object with mass including humans, pencils and even electrons and protons. However, their gravitational field is so weak that in most situations, it is considered non-existent.