Question

Study the statements given below:
(i) Electromagnets can be made more powerful than ordinary bar magnets.
(ii) Soft iron is easy to magnetize and demagnetize.
(iii) The poles of an electromagnet are not affected by the direction of the current.
Which of the above statements about the electromagnets are correct?

• A. (i), (ii) and (iii)
• B. Only (ii) and (iii)
• C. Only (i) and (iii)
• D. Only (i) and (ii)

Answer 1

The correct option is D

Only (i) and (ii)

Electromagnets are more powerful than ordinary bar magnets. The strength of a magnetic field of an electromagnet depends on:

(i) the number of the coiled conductor

(ii) the strength of the current

(iii) the area of the cross-section of the soft iron placed inside the coil

Since soft iron has high susceptibility and low retentivity it is easy to magnetize and demagnetize. Soft iron loses its magnetism as soon as the current stops flowing and hence it is a temporary magnet.
The poles of an electromagnet depend upon the direction of current flowing through a circuit. The polarity of an electromagnet can be reversed by reversing the flow of current through the coil.