Question

a. Why are electromagnets used in industrial cranes instead of permanent
magnets?
b. Why are coil of wires used in electromagnets instead of straight wires?​

Answer 1

Answer:

ANS.a)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. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.

ANS.b)A coil of a wire is used in an Electromagnet instead of just a straight wire because coil has many number of loops of wire and each loop of wire behave as a magnet. When an electric current flows through the coil , it creates a magnetic field. This produces temporary magnetism in the iron core.

Answer 2

Explanation:

(a) Because electromagnet can be made more Powerful by modifying electric current across it but strength of permanent magnet is fixed.

(b)A coiled wire carrying current acts like a magnet. Then why is a coil of a wire is used in an Electromagnet instead of just a straight wire?