Place a round magnet on wooden table in 2 different positions. Place a card over it and sprinkle
very little iron powder gently on entire surface of the card. Tap the card at one corner gently. Iron
powder shows magnetic lines of force.
When we place magnet in vertical position, we get circles on both sides of magnet. Why are
the lines forming circles around magnet?
a. It is due to shape of magnet. As it is round, the lines are also circular.
b. Magnetic lines are formed due to magnetic field of the Earth. As the Earth is spherical in
shape, the lines are circular.
c. Each particle of iron powder experiences magnetic force from both poles of magnet. All
particles align to these poles, making the lines circular.
d. Each particle of iron has only one pole, like N or S. They stick to each other forming lines
Answers
Answer:
Magnets and Magnetization
People have been aware of magnets and magnetism for thousands of years. The earliest records date back to ancient times, particularly in the region of Asia Minor called Magnesia—the name of this region is the source of words like magnet. Magnetic rocks found in Magnesia, which is now part of western Turkey, stimulated interest during ancient times. When humans first discovered magnetic rocks, they likely found that certain parts of these rocks attracted bits of iron or other magnetic rocks more strongly than other parts. These areas are called the poles of a magnet. A magnetic pole is the part of a magnet that exerts the strongest force on other magnets or magnetic material, such as iron. For example, the poles of the bar magnet shown in Figure 20.2 are where the paper clips are concentrated.
Explanation: