Hint: We will start with the definition of the magnetic field. So a magnetic field is generally concluded as an area or region where the magnetic force acts and the magnetic force is generally developed due to the moving charge or also because of some magnetic material.
Complete step by step answer
It is known that when a conducting wire is connected to the battery and when current flows through it, there exists a magnetic field that is developed around the wire. This magnetic field is produced due to the electric charges that are flowing through the wire.
Electric current is generally defined as the rate of flow of charges across the conductor in a unit of time. We know that the electric field produced due to stationary charges is found to be proportional to the magnitude of the charges. Hence we can apply the same principle here that the magnetic fields produced due to moving charges are found to be proportional to the current as a result magnetic field is produced around the current-carrying conductor.
Now the characteristics of the magnetic field due to current carrying straight conductor can be given as follows:
-The magnetic fields lie in a plane that is perpendicular to the straight conductor.
-The magnetic field lines encircle around the current-carrying straight conductor whose direction can be given by the right-hand thumb rule where the thumb represents the direction of current and the fingers wrapped around the wire shows the direction of magnetic fields.
-If the direction of current is reversed then the direction of magnetic fields is also reversed.
-The magnetic field strength is directly proportional to the magnitude of the current flowing through the conductor.
-The magnetic field strength decreases as the distance from any point from the wire is increased.
These are the basic characteristics that govern the magnetic fields produced around a straight current-carrying conductor.
A magnetic field consists of both magnitude and direction. Hence, it is considered as a vector quantity. The magnetic field produced due to a current-carrying conductor depends on the distance of the point from the conductor and the magnitude of the current flowing through the conductor.