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| Heat and Temperature |
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| Heat energy is present in every object above absolute zero. How do we know that heat is present in every object? Temperature of the body is an indication. |
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| (Absolute zero is the lowest temperature possible and is equal to -273oC). |
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| Are heat and temperature one and the same? |
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| No. They are different. Heat is a form of energy and temperature represents the degree of hotness of a body. We can say, 'Heat is the cause and temperature is the effect'. |
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| Consider this example- A and B are two glass vessel interconnected by tube with a valve. In the first picture the vessels are filled with water to different levels. The valve is closed. In picture (2), the valve is open. We observe that water flows from vessel A (in which water level is higher) to vessel B (in which water level is lower) until the levels are
equalized. Thus, water flows from higher level to a lower level until the levels are equalized. |
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| Water flows from higher level to lower level |
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| Similarly, if two substances at different temperatures are mixed, heat flows from hotter body to the colder one until their temperatures are
equalized. |
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| Thus, we can say that, 'temperature is that condition which decides the direction of heat flow when two bodies are mixed together'. |
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