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प्रश्न
It is difficult to cook vegetables on hills and mountains. Explain the reason.
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उत्तर
This is because at high altitudes atmospheric pressure is low; therefore, boiling point of water decreases and so it does not provide the required heat energy for cooking.
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संबंधित प्रश्न
Boiling takes place from the
Describe an experiment to demonstrate that water absorbs heat during boiling at a constant temperature.
A certain quantity of water is heated from 20°C to 100°C. Its temperature is recorded after each 1 minute. The observations are:
| Time (in minute) | Temperature (in °C) |
| 0 | 20 |
| 1 | 30 |
| 2 | 40 |
| 3 | 50 |
| 4 | 60 |
| 5 | 70 |
| 6 | 80 |
| 7 | 90 |
| 8 | 100 |
| 9 | 100 |
| 10 | 100 |
| 11 | 100 |
| 12 | 100 |
A pressure cooker is based on the principle that boiling point of water increases with the ______.
Assertion: The process of conversion of liquid water to its vapours by heating the liquid is called boiling.
Reason: The process of conversion of water vapours to liquid by cooling the vapours is called condensation.
During summer, water kept in an earthen pot becomes cool because of the phenomenon of
____________ is the change of solid state directly to vapour state without going through the ____________ state.
Alka was making tea in a kettle. Suddenly she felt intense heat from the puff of steam gushing out of the spout of the kettle. She wondered whether the temperature of the steam was higher than that of the water boiling in the kettle. Comment.
We would have observed that the plate that covers the cooked food items has water droplets inside. Why? Explain.
A liquid changes into a gas at a constant temperature known as its ______.
