Magnetism

Magnetic field due to a straight current carrying conductor

When current is passed through a straight current-carrying conductor, a magnetic field is produced around it. Using the iron filings, we can observe that they align themselves in concentric circles around the conductor.

Right-hand thumb rule

If a straight conductor is held in the right hand in such a way that the thumb points along the direction of the current, then the tips of the fingers or the curl of the fingers show the direction of magnetic field around it.

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 of small straight segments. Every point on the wire carrying current gives rise to a magnetic field that appears as straight lines at the center.

Magnetic field due to current in a solenoid

A solenoid is a coil of many circular winding wrapped in the shape of a cylinder. When current is passed through it, it behaves similar to a bar magnet, producing a very similar field pattern as that of a bar magnet. To increase the strength a soft iron core is used.