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प्रश्न
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?
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उत्तर
- Heat is transferred from hot object to cold object.
- During the transfer of heat from hot object to cold object we perceive the principle of heat exchange.
- As inside the heat resistant box, the heat lost by hot object exactly equals heat gained by cold object, principle of heat exchange is stated as:
In an isolated system,
Heat energy lost by hot object = Heat energy gained by cold object. - Specific heat of the substance is measured using the principle of heat exchange.
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संबंधित प्रश्न
Given below are observations on molar specific heats at room temperature of some common gases.
| Gas |
Molar specific heat (Cv) (cal mol–1 K–1) |
| Hydrogen | 4.87 |
| Nitrogen | 4.97 |
| Oxygen | 5.02 |
| Nitric oxide | 4.99 |
| Carbon monoxide | 5.01 |
| Chlorine | 6.17 |
The measured molar specific heats of these gases are markedly different from those for monatomic gases. Typically, molar specific heat of a monatomic gas is 2.92 cal/mol K. Explain this difference. What can you infer from the somewhat larger (than the rest) value for chlorine?
Define heat capacity and state its SI unit.
A liquid X has the maximum specific heat capacity and is used as a coolant in Car Radiators. Name the liquid X.
What do you mean by the following statement?
The specific heat capacity of copper is 0. 4 Jg-1 K-1?
What change in heat energy occurs when lead at its melting point
solidifies without change in the temperature?
Fill in the following blank using suitable word:
SI unit of heat is .........
Write two advantages of high specific heat capacity of water.
Explain, why does a wise farmer water his fields, if forecast is forst?
A substance is in the form of a solid at 0°C. The amount of heat added to this substance and the temperature of the substance are plotted on the following graph:
If the specific heat capacity of the solid substance is 500 J/kg °G, find from the graph, the mass of the substance.
How much heat energy is necessary to raise the temperature of 5 kg of water from 20°C to 100°C?
Explain how heat capacity of a solid can be determined by the method of mixture.
Consider the statement given below and choose the correct option.
Assertion: Radiation is a form of heat transfer which takes place only in vacuum.
Reason: The thermal energy is transferred from one part of a substance to another part without the actual movement of the atoms or molecules.
A piece of lead weighing 500 g gives out 1200 calories of heat when it is cooled from 100° C to 20° C. Find its specific heat.
J/Kg °C is the unit of specific heat capacity.
Find the odd one out:
The difference between the two molar specific heats of gas is 9000 J/kg K. If the ratio of the two specific heats is 1.5, calculate the two molar specific heats.
A block of ice of mass 120 g at temperature 0°C is put in 300 gm of water at 25°C. The xg of ice melts as the temperature of the water reaches 0°C. The value of x is ______.
[Use: Specific heat capacity of water = 4200 Jkg-1K-1, Latent heat of ice = 3.5 × 105 Jkg-1]
Give one example where high specific heat capacity of water is used as heat reservoir.
In the method of mixtures, a hot metal is dropped into cold water and the mixture reaches a final temperature. Which principle is used to find the specific heat of the metal?
