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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?
- Measuring the property of which substance this principle is used?
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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?
Calculate the mass of ice required to lower the temperature of 300 g of water 40°C to water at 0°C.
(Specific latent heat of ice = 336 J/g, the Specific heat capacity of water = 4.2J/g°C)
What do you understand by the following statements:
The heat capacity of the body is 60JK-1.
What do you understand by the following statements:
The specific heat capacity of lead is 130 Jkg-1K-1.
A solid metal weighing 150 g melts at its melting point of 800 °C by providing heat at the rate of 100 W. The time taken for it to completely melt at the same temperature is 4 min. What is the specific latent heat of fusion of the metal?
Explain the meaning of green house effect.
State three ways to minimize the global warming.
Name and state the principle used to measure the specific heat capacity of a substance.
A piece of iron of mass 2.0 kg has a heat capacity of 966 J K-1. Find its specific heat capacity in S.I unit.
Name the substance which has maximum specific heat capacity.
Specific heat capacity of substance A is 3.8 J g-1 K-1whereas the specific heat capacity of substance B is 0.4 J g-1 K-1. Which of the two is a good conductor of heat? How is one led to this conclusion?
A certain amount of heat Q will warm 1 g of material X by 3°C and 1 g of material Y by 4°C. Which material has a higher specific heat capacity?
The molar specific heat of a gas at constant volume is 12307.69 J kg-1 K-1. If the ratio of the two specific heats is 1.65, calculate the difference between the two molar specific heats of gas.
The SI unit of specific heat is _______.
Two uniform brass rods A and B of length land 2l and radii 2r and r respectively are heated to the same temperature. The ratio of the increase in the volume ofB to that of A is ____________.
A geyser heats water flowing at a rate of 2.0 kg per minute from 30°C to 70°C. If the geyser operates on a gas burner, the rate of combustion of fuel will be ______ g min-1.
[Heat of combustion = 8 × 103 Jg-1 Specific heat of water = 4.2 Jg-1°C-1]
Thermal capacities of substances A and B are same. If mass of A is more than mass of B then:
Which substance will have more specific heat capacity?
Prove the Mayer's relation `C_p - C _v = R/J`
