Electricity and magnetic are studied separately from long time. In 18 century the scientist realised that magnetism and electric current are interrelated to each other. They unified these two concepts. Due to unification of this two concepts led to dramatical change in technology.
Orested found that the deflection in a magnetic needle placed near current carrying conductor. After that Maxwell, Faraday did research on this concept. Faraday was the genius experimental physicists. He publish series of experiments on electromagnetism. After performing series of experiments, they realised that current carrying conductor creates magnetic field around it. To understand this phenomenon we have to perform an experiment.
Consider a current carrying conducting Wire AB. Connect it to a battery with the help of key. Place a magnetic needle near to that wire AB. Make the arrangement is as shown in figure.
On the key and allow to flow current in wire AB and see the deflection in magnetic needle.
Now, reverse the connections of battery and observe the deflection in magnetic needle. At this time magnetic needle deflects at opposite direction.
Increase the value of current by replacing battery. At this time magnetic needle reflect much as compare to above.
From above experiment, we conclude that
- A current carrying conductor creates magnetic field around it.
- The direction of magnetic filed due to current carrying conductor is depend on direction of current. When we reverse the direction of current flowing in a wire then the direction of magnetic field also reverse.
- Magnitude of magnetic field due to current carrying conductor is depend on value of current flowing in a conducting wire.
- Current carrying wire and magnetic field produced due to that are lies in different plane.