Question

Two identical-looking iron bars A and B are given, one of which is definitely known to be magnetized. How would one ascertain whether or not both are magnetized? If only one is magnetized, how does one ascertain which one?

Answer 1

Hint: We know that the magnetic field is an invisible vector force, which influences an electric charge and a few magnetic metals. Since it’s a vector clearly, it has both direction and magnitude. A magnet has two different poles, namely the North and the South Pole.

Complete answer
A magnet is metal that can produce a magnetic field. It has two poles, namely the North and the South Pole on two sides of the metal. Generally, the like poles repel, while the unlike poles attract. This is saying that, North Pole of one magnet repels from the north pole of another magnet, this is true for two South Pole also. However, if a North Pole of one magnet is brought near the south pole of another magnet, then they attract. This special property possessed by a magnetic material is called the magnetic effect.
Also, there are two types of magnets on the basis of their magnetic strength namely the permanent and the temporary magnets. A permanent magnet produces a strong magnetic field always, whereas the magnetic field produced by a temporary magnet is short spanned and weak.
To identify the magnetised rod, we can suspend both the given rods using a light thread. Since the earth is also a huge magnet, which has a north and south pole, we can say that it produces an magnetic field. Then the rod which rests at the geographical north-south direction is said to be magnetised.

Note: We know that the magnetic field is a vector quality, and hence has both direction and magnitude. We can also say that the direction of the magnetic field is given from north to south outside the magnet and south to north inside the metal.