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प्रश्न
How does green house effect help in keeping the temperature of earth’s surface suitable for living of human beings?
उत्तर
From sun, we receive 1366W m-2 energy at the top of our earth's atmosphere, out of which only 235Wm-2 energy reaches near the earth's surface. The earth and ocean surface absorbs 168 W m-2 energy and only 67 W m-2 energy remains in the lower atmosphere. With this much energy received on earth surface, its actual surface temperature would have been around -180C which is quite uncomfortable for human living. Fortunately the greenhouse gases present in the earth's atmosphere contribute in trapping the heat energy within the atmosphere and they produce an average warming effect of about 330C to keep the effective temperature around 150C. So, greenhouse effect helps in keeping the temperature of earth's surface suitable for living of human beings.
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संबंधित प्रश्न
A geyser heats water flowing at the rate of 3.0 litres per minute from 27 °C to 77 °C. If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combustion is 4.0 × 104 J/g?
Specific heat capacity of substance A is 3.8 J g-1K-1 whereas the specific heat capacity of substance B is 0.4 J g-1 K-1
(i) Which of the two is a good conductor of heat?
(ii) How is one led to the above conclusion?
(iii) If substances A and B are liquids then which one would be more useful in car radiators?
How will you prove experimentally that different substances have different specific heat capacities?
The ratio of specific heat capacity to molar heat capacity of a body _____________ .
Give one example where high specific heat capacity of water is used as cooling.
State factors on which the amount of heat radiated by a body depends.
Read the passage and answer the questions based on it.
If heat is exchanged between a hot and cold object, the temperature of the cold object goes on increasing due to gain of energy and the temperature of the hot object goes on decreasing due to loss of energy. The change in temperature continues till the temperatures of both objects attain the same value. In this process, the cold object gains heat energy and the hot object loses heat energy. If the system of both the objects is isolated from the environment by keeping it inside a heat-resistant box then no energy can flow from inside the box or come into the box. In this situation, we get the following principle.
Heat energy lost by the hot object = Heat energy gained by the cold object. This is called the ‘Principle of heat exchange’.
- Where does heat transfer take place?
- In such a situation which principle of heat do you perceive?
- How can this principle be explained in short?
- Which property of the substance is measured using this principle?
What is specific heat capacity?
Two blocks P and Q of different metals having their mass in the ratio 2 : 1 are given same amount of heat. Their temperature rises by same amount. Compare their specific heat capacities.
Give one example where high specific heat capacity of water is used as heat reservoir.
