Question

In olden days, sailors used to find direction by suspending a piece of _________.

Answer 1

Hint: A bar magnet is just like another magnet. It is a rectangular piece of an object which is made up of metals like iron, steel, or some other ferromagnetic substances. A bar magnet shows permanent magnetic properties. Just like other magnets, it has two poles- one is the North pole and the other one is the South pole.

Complete step by step answer:
Step I:
As said above, a bar magnet has two poles, so whenever it is suspended freely with the help of a thread or string, it always points in the North-South direction.
This means that the North pole of the bar magnet aligns itself towards the magnetic North pole of the Earth and the South pole of the magnet aligns in the South direction of the magnetic pole of the Earth.
During the olden days, when the compass was not developed to find direction, the sailors used to find the direction using a bar magnet. They used to suspend it freely with the help of a thread and find the direction when they travel. They always keep the bar magnet with them while traveling.
Bar magnets also have their uses these days. They are used indoors in refrigerators, or to pick up small metallic objects like metals or nails from the scrap. Also, they are used in needles of the magnetic compass in order to find the direction.

$\therefore$In the olden days, sailors used to find direction by suspending a piece of a bar magnet.

Note:
It is to be noticed that the bar magnet is not similar to an electromagnet. Since the bar magnet has a permanent magnetic field of its own which it never loses. But electromagnet is a coil of wire which behaves like a magnet when current is passed through it.