GEOLOGY

Detailed explanation-1: -Magnetism is what happens when a substance gives off an invisible magnetic force. There are two main types of magnetism, ferromagnetism and diamagnetism. Ferromagnetism is what makes objects like iron, nickel and cobalt attracted to magnets (and become permanent magnets themselves).

Detailed explanation-2: -The invisible area around a magnetic object that can pull another magnetic object toward it or push another magnetic object away from it is called a magnetic field. It’s kind of like those invisible “force fields” that surround an object with invisible power in sci-fi movies and books.

Detailed explanation-3: -The correct answer is D. Magnet has an invisible magnetic field which attracts objects made of iron and nickel.

Detailed explanation-4: -Magnetic forces are non contact forces; they pull or push on objects without touching them. Magnets are only attracted to a few ‘magnetic’ metals and not all matter. Magnets are attracted to and repel other magnets.