Answer in answer in one or two words/sentence.
1. Why do we use electromagnets, when they have to be magnetised every time they are used?
2. Why do we make artificial magnets?
3. What is a magnetic keeper? Why it is used?
4. Discuss the properties of magnetic field.
5. State any two advantages of artificial magnets over natural magnets.
Answers
Answer:
1. The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. ... Electromagnets are also employed in industry for picking up and moving heavy iron objects such as scrap iron and steel.
2.An artificial magnet is a magnetized piece of iron (or other magnetic material). Artificial magnets are required because natural magnets have odd and irregular shape and they are not magnetically very strong. Artificial magnets can be given desired shape and made very strong.
3.A magnet keeper, also known historically as an armature, is a bar made from magnetically soft iron or steel, which is placed across the poles of a permanent magnet to help preserve the strength of the magnet by completing the magnetic circuit; it is important for magnets that have low magnetic coercivity, such as ...
4.Magnetic field lines never intersect with each other. Magnetic field lines form a closed-loop. Field lines have both direction and magnitude at any point on the field. Therefore, magnetic field lines are represented by a vector.
5.Magnetism | Short/Long Answer Questions
Solution: Artificial magnets are preferred over natural magnets because they can be made of any strength and can be magnetised or demagnetised by a simple click of a switch.