Magnetic Field Due to Current Carrying Conductor

When current is passed through a straight current-carrying conductor, a magnetic field is produced around it. The field lines are in the form of concentric circles at every point of the current-carrying conductor. And we can find the direction of the magnetic field, in relation to the direction of electric current through a straight conductor can be depicted by using the Right-Hand Thumb Rule also called as Maxwell Corkscrew Rule.

This rule states that ‘If a current-carrying conductor is held by the right hand, keeping the thumb straight and if the direction of electric current is in the direction of thumb, then the direction of wrapping of other fingers will show the direction of the magnetic field.’

Magnetic field due to current through a circular loop

The right-hand thumb rule can be used for a circular conducting wire as well as it comprises small straight segments. Every point on the wire carrying current gives rise to a magnetic field around it would become larger and larger as we move away from the wire and by the time we reach the center of the circular loop, the arcs of these circles would appear as a straight line 

Magnetic field and number of turns of the coil

The magnitude of the magnetic field gets summed up with the increase in the number of turns of the coil. If there are ‘n’ turns of the coil, the magnitude of the magnetic field will be ‘n’ times the magnetic field in case of a single turn of the coil.

The strength of the magnetic field at the center of the loop (coil) depends on:

• The radius of the coil: The strength of the magnetic field is inversely proportional to the radius of the coil. If the radius increases, the magnetic strength at the center decreases
• The number of turns in the coil: As the number of turns in the coil increase, the magnetic strength at the center increases, because the current in each circular turn is having the same direction, thus, the field due to each turn adds up.
• The strength of the current flowing in the coil: As the strength of the current increases, the strength of three magnetic fields also increases.

Read More: Magnetic Field Due to Solenoid and Toroid

Magnetic field is considered a region where the force of magnetism is present. This magnetic force is generally created by a moving charge or magnetic substance. H. C. Oersted made the discovery that a current-carrying conductor creates a magnetic influence all around it in the early years of the 19th century. Although science and technology were not as advanced as they are now, it was already known from observations that the effect of lightning striking a ship may result in the compass needles malfunctioning, which would interfere with the navigation system. Let’s learn more about the magnetic field due to the current-carrying conductor in this article!