Question

Which among the following is made of soft iron?
A. Permanent magnet
B. Electromagnet
C. Temporary magnet
D. All

Answer 1

Hint:In electronic, electromechanical and magnetic equipment such as electromagnets, transformers, electric motors, generators, inductors, magnetic recording heads, and magnetic assemblies, a magnetic core is a piece of magnetic material with high magnetic permeability used to confine and direct magnetic fields. It is composed of iron-like ferromagnetic metal, or ferromagnetic compounds such as ferrites. The high permeability allows the magnetic field lines to be localized in the central layer, relative to the surrounding air. A current-carrying coil of wire around the core is also generated by the magnetic field.
The use of a magnetic core in an electromagnetic coil will increase the magnetic field strength by a factor of several hundred times what it would be without the core. Magnetic centers, however, have side effects that must be taken into consideration. They trigger energy losses, called core losses, in alternating current (AC) devices, owing to hysteresis and eddy currents in applications such as transformers and inductors. 'Soft' magnetic materials, such as silicon steel or ferrite, with low coercivity and hysteresis, are typically used in cores.

Complete step by step solution:
When the current begins to flow, the soft iron inside the coil makes the magnetic field stronger as it itself becomes a magnet. Soft iron is appropriate, since as soon as the current ceases moving, it lacks its magnetism.
An electromagnet is a magnet that is temporary. As long as electrical power is transmitted into its solenoid, it preserves its magnetic property. In the electromagnet, a soft iron core is used and as soon as current is absorbed from it, it lacks its magnetization. It has a magnetic field that is very solid. Since it consists of a solenoid, shifting current changes the intensity of the field and also the direction.

Hence option B is correct.

Note:The electromagnet varies absolutely from the permanent magnet. The distinction between the permanent magnet and the electromagnet is the strength and magnetic field. In Electromagnet, a wire-wound coil produces the magnetic field, but the Permanent (Bar) Magnet magnetic field will not be modified. On the other hand, the strength of the Electromagnet varies according to the movement of electric current through it. The strength of the Permanent Magnet depends on the material used for its construction. It is not important to alter the poles of a permanent magnet. However, it is possible to adjust the poles of an electromagnet magnet.