Permanent magnet Temporary magnet Magnetic properties are retained permanently. It is a magnet with temporary magnetism .The magnetism parts as long as current flows in the coil around it. It is comparatively a weak magnet. It is stronger . . .
Each line is a closed and continuous curve. Magnetic lines of forces originate from the North Pole and terminate at the South Pole. They never intersect each other. They are crowded near the poles where the magnetic field is strong. They affect the magnetic compass needle. . . .
The magnetic effect of electric current is known as electromagnetic effect. It is observed that when a compass is brought near a current carrying conductor the needle of compass gets deflected because of flow of electricity. This shows that electric current produces a magnetic effect. . . .
An electromagnet is a magnet that runs on electricity. A magnet produced by passing an electric current through a coil (a length of wire wound closely together is called a coil) wound around a soft iron core is called an electromagnet. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric cu . . .
An electromagnet’s strength depends on the number of turns of wire and the amount of current passing through it. An electromagnet is not a permanent magnet. Its magnetism lasts only while a current passes through its coil. Once the current stops, the iron core loses its magnetism. . . .
Electromagnets have numerous uses some common ones are given below: Cranes with strong electromagnets are used to pick up iron objects. To put them down Electromagnets are also used for separating objects made of magnetic materials from others. A thin iron strip attracted by an electromagnet produces a sound as it strikes against the electroma . . .