Hinglish

Attraction and Repulsion

Class 6 Science · Chapter 4: Exploring Magnets · NCERT Curiosity section 4.4

Learn

Rohan places two bar magnets on toy cars. When he brings the N pole of one near the S pole of the other, the cars roll towards each other. When he turns one car round so that N faces N, the cars roll apart!

Unlike poles attract (N and S pull together). Like poles repel (N and N, or S and S, push apart). This push and pull happens even without touching, and even through paper or wood.

N–S → attract · N–N, S–S → repel

How can you tell if a metal bar is really a magnet? An iron bar is attracted by both poles of a magnet. But only a magnet can be repelled. So repulsion is the sure test of a magnet.

Explore: make the magnets attract and repel.

  1. Make the magnets repel.
  2. Make them attract with N facing S.

Remember

  • Like poles repel; unlike poles attract.
  • Repulsion is the sure test of a magnet: iron is only ever attracted.

Quick check

Two magnets push each other away. Which ends are facing?

  1. Like poles (N–N or S–S)
  2. Unlike poles (N–S)
  3. The middles
  4. Any ends at all
Answer

Like poles (N–N or S–S). Like poles repel; unlike poles attract.

Think about it

You have two identical-looking bars. One is a magnet, the other is plain iron. With no other objects, how can you tell which is the magnet?

One answer

Touch the end of bar A to the middle of bar B. If they pull strongly, A is the magnet (a magnet's ends are strong, an iron bar's middle has no pull). If there is little pull, B is the magnet: its middle is weak, and A's end is just plain iron.

Practice

Practise with fresh questions at three levels (easy, medium, hard), some answered hands-on, with hints and worked answers. Get 4 of your last 5 right to finish the topic.