Nate Core Practice Test

What establishes a magnetic field around a conductor?

1. When voltage is applied

2. Whenever current flows through it

3. When the conductor is coiled

4. When it is placed in a magnetic field

The correct answer is: Whenever current flows through it

The establishment of a magnetic field around a conductor is directly linked to the flow of electric current through it. When current passes through a conductor, it creates a magnetic field due to the movement of charged particles. The strength and direction of this magnetic field can be determined by the right-hand rule, which states that if you grip the conductor with your right hand such that your thumb points in the direction of the current, your fingers will curl in the direction of the magnetic field lines. Applying voltage influences the machinery, but it is the actual flow of electric current that induces the magnetic field. Additionally, coiling a conductor, as seen in electromagnets, enhances the magnetic field created, but the initial requirement for a magnetic field to exist is the current flow itself. Placing a conductor in an external magnetic field does not establish a magnetic field around it but could induce a current in it according to electromagnetic induction principles.