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प्रश्न
Give examples to explain the difference between changes that can or cannot be reversed.
उत्तर
To explain the differences between changes that can or cannot be reversed, some examples are given below:
(i) If we inflate a balloon, the size and shape of the balloon undergo a change. However, the original size and shape of the balloon can be obtained back by allowing the air to escape from the balloon. This means that the change that occurs by inflating a balloon can be reversed. But, if the balloon bursts after being inflated, then its original size and shape cannot be obtained back. Thus, in this case, the change cannot be reversed.
(ii) If we fold a piece of paper, then the shape and size of the paper undergo a change. In this case, the original shape and size of the original paper can be obtained back. Thus, this change can be reversed. However, if we cut the piece of paper, the change in the shape and size of the paper cannot be reversed.
(iii) After we roll out a chapatti from a ball of dough, the chapatti can be converted back into a ball. Thus, the change occurring here can be reversed. But, if we cook the chapatti on a Tawa, then it cannot be converted back into a ball of dough. Thus, the change is irreversible.
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संबंधित प्रश्न
Very Short Answer Type Question:
Some common changes are given in the below Table. Which of these changes do you think can be reversed?
| Change | Can be reversed |
| (i) Raw egg to boiled egg | Yes/No |
| (ii) Batter to idli | |
| (iii) Wet clothes to dirty clothes | |
| (iv) Woollen yarn to knitted sweater | |
| (v) Grain to its flour | |
| (vi) Cold milk to hot milk | |
| (vii) straight string to a cold string | |
| (viii) Bud to flower | |
| (ix) Milk to paneer | |
| (x) Cow dung to biogas | |
| (xi) stretched rubber band to its normal size | |
| (xii) Melting of ice-cream |
A stretched rubber band comes back to normal shape. It is an example for ________.
Circle the odd one.
What is reversible change?
Formation of curd from milk is
A drawing sheet changes when you draw a picture on it. Can you reverse this change?
Which is reversible change?
What are reversible changes?
Salt can be separated from its solution (salt dissolved in water), because
Paheli mixed flour and water and
- made a dough,
- rolled the dough to make a chapati,
- baked the chapati on a pan,
- dried the chapati and ground it in a grinder to make powder.
Identify the changes (i) to (iv) as the changes that can be reversed or that cannot be reversed.
