GEOLOGY

Detailed explanation-1: -It never remains continuously flowing through the loop. In other words, we can say that electromagnets act as the magnet when the current flows through it. ∴ Option (B) is the correct answer.

Detailed explanation-2: -A permanent magnet if kept and used in optimum working conditions will keep its magnetism for years. It’s estimated that neodymium magnets only lose approximately 5% of their magnetism every 100 years.

Detailed explanation-3: -An electro magnet is a temporary magnet made by winding wire around an iron core. When current flows in the coil the iron becomes a magnet, and when the current is turned off it looses it’s magnetic properties.

Detailed explanation-4: -An electromagnet is made by winding an insulated copper wire around a soft iron core either in the shape of a solenoid or U-shape and passing current through it. The strength of magnetic field of an electromagnet depends on: The number of turns of wire wound around the coil, and.

Detailed explanation-5: -An electromagnet is called a temporary magnet because it produces a magnetic field only when the current flows in its coil. The magnetic field vanishes when the current is switched off.