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प्रश्न
A drawing sheet changes when you draw a picture on it. Can you reverse this change?
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उत्तर
If we draw a picture on a drawing sheet with a pencil, we can get back the original drawing sheet by erasing the drawing with an eraser. In this case, the change can be reversed.
However, if we draw with a pen, then the original drawing sheet cannot be obtained back because we cannot erase ink. Hence, in this case, the change cannot be reversed.
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 |
Choose the odd one out. Give reason for your choice.
Inflating a balloon, popping a balloon, fading of wall paint, burning of kerosene
Periodical removal of one of the products of a reversible reaction increases the yield.
Water on ______ changes to ice and on ______ comes back to water.
Evaporation of water is a reversible change.
The burning of the paper is an irreversible change.
Give one example of change which occurs on heating but can be reversed.
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.
Choose the odd one out. Give a reason for your choice.
Choose the odd one out. Give a reason for your choice.
