Question

Mark the correct difference between a permanent magnet and an electromagnet.

• A. Permanent magnet does not require any external electric supply to produce the field. But their magnetic field is normally weaker than that of an electromagnet.
• B. Hence, permanent magnets are relatively bulky in size compared to electromagnets.
• C. The applications of permanent magnet in the field of engineering are quite limited.
• D. All

Answer 1

The correct option is D All

Permanent magnet does not require any external electric supply to produce the field. But their magnetic field is normally weaker than that of an electromagnet. Hence, permanent magnets are relatively bulky in size. The strength of the field cannot be varied as per requirement. The field of these magnets are also not everlasting, it will be loosened over a period of time. They also lose their magnetism, if they get subjected to physical shock or vibration. Because of these many disadvantages, the applications of permanent magnet in the field of engineering are quite limited.