Magnetism - JSS3 Basic science Past Questions and Answers - page 2

Loadstone, also known as magnetite, was significant for ancient sailors and travelers because it naturally aligns itself with Earth's magnetic field, allowing them to navigate and find direction, particularly across oceans and unfamiliar lands. It served as a primitive compass, aiding navigation and exploration.

Like magnetic poles repel each other. When brought close together, they exert a force that pushes them apart. This behavior is fundamental to the laws of magnetism and helps explain the behavior of magnets and magnetic materials.

The main component of loadstone is iron oxide. It is composed mainly of iron and oxygen atoms, giving it its magnetic properties. Other minerals may also be present, but iron oxide is the primary component responsible for loadstone's magnetism.

Magnetic field lines around a magnet flow from the north pole to the south pole outside the magnet. These lines form closed loops, indicating the direction of the magnetic field. This property helps visualize and understand the behavior of magnetic fields.

According to the inverse square law, the strength of the magnetic force between magnets decreases with the square of the distance between them. This means that as the distance between magnets increases, the magnetic force weakens proportionally.

Magnetic induction is the process by which a magnetic material becomes magnetized when placed in a magnetic field. Essentially, the magnetic field induces magnetic properties in the material, aligning its atomic or molecular magnetic moments. This phenomenon is the basis for the operation of electromagnets, transformers, and other magnetic devices.