GEOLOGY

Detailed explanation-1: -Answer: The statement “Magnetic lines of force are invisible” is true.

Detailed explanation-2: -Two opposite poles will attract each other, and two poles that are the same (two north poles or two south poles) will push apart. Although the magnetic field is invisible, it can be seen indirectly. Iron filings placed in the magnetic field will show where the lines of force lie.

Detailed explanation-3: -A magnetic field is an invisible force field created by a magnet or as a consequence of the movement of electric charges (flow of electricity).

Detailed explanation-4: -The given statement about the magnetic field is TRUE. The magnetic field is the area where a magnet has the greatest influence on other objects, such as magnetic materials or electric current.

Detailed explanation-5: -Magnetic fields are not visible because it was not important during evolution to acquire that capability. That makes sense when you look where to find magnetic fields in nature. There is the field of Earth, that can be used for navigation.