Magnetic Effects of Electric Current | Class 10 Science Notes

Magnetic Effects of Electric Current

In the previous chapter on Electricity, we studied the heating effect of electric current. However, electric current produces other effects as well, one of which is its magnetic effect. When an electric current passes through a conductor, it behaves like a magnet and produces a magnetic field around it. This fundamental link between electricity and magnetism was first discovered by Hans Christian Oersted in 1820, when he observed that a compass needle deflected when placed near a current-carrying wire. This discovery laid the foundation for the field of electromagnetism and led to many technological advancements such as radio, television, and fiber optics.

To observe this magnetic effect of electric current, an activity can be performed where a straight copper wire is placed perpendicular to the plane of a paper and a compass needle is placed near it. When current flows through the wire, the compass needle deflects, indicating the presence of a magnetic field produced by the current. This shows that electricity and magnetism are interrelated phenomena. The unit of magnetic field strength is named 'oersted' in honor of Hans Christian Oersted's contribution.

This chapter explores magnetic fields, their properties, how they are produced by electric currents, and the forces experienced by current-carrying conductors in magnetic fields. It also discusses electromagnets and their applications, including their use in medicine and domestic electric circuits.

📊 Diagram: Figure 12.1 Compass needle is deflected on passing an electric current through a metallic conductor; Figure 12.2 Reprint 2026-27

🧪 Activity: Activity 12.1: Passing current through a straight copper wire and observing compass needle deflection.

🔗 Connection: Leads to the study of magnetic fields and field lines in the next section.