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प्रश्न
State factors on which the amount of heat radiated by a body depends.
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उत्तर
The amount of heat radiated by a body depends on:
- The absolute temperature of the body (T)
- The nature of the body – the material, nature of the surface - polished or not, etc.
- The surface area of the body (A)
- Time duration for which body emits radiation (t).
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संबंधित प्रश्न
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 property of water makes it an effective coolant?
50 g of metal piece at 27°C requires 2400 J of heat energy so as to attain a temperature of 327°C . Calculate the specific heat capacity of the metal.
A liquid X has the maximum specific heat capacity and is used as a coolant in Car Radiators. Name the liquid X.
The S.I. unit of specific heat capacity is ______.
The specific heat capacity of water is :
Name the radiations for which the green house gases are opaque ?
What is meant by global warming?
Define the term 'specific heat capacity' and state its unit.
The product of mass and specific heat is known as ..........
A liquid X has specific heat capacity higher than the liquid Y. Which liquid is useful as heat reservoir to keep juice bottles without freezing?
What are the factors on which the quantity of heat given to a body depends?
The farmers fill their fields with water in winter. Give reason.
Explain, why temperature in hot summer, falls sharply after a sharp shower?
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?
Ice-cream at 0°C feels colder than water at 0°C. Give reason for this observation.
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.
A piece of ice is heated at a constant rate. The variation of temperature with heat input is shown in the graph below:
(i) What are represented by AB and CD?
(ii) What conclusion can you draw regarding the 110°c nature of ice from the above graph?
A. hot solid of mass 60 g at 100°C is placed in 150 g of water at 20° C. The final steady temperature recorded is 25°C. Calculate the specific heat capacity of the solid. [Specific heat capacity of water = 4200 J kg-1 °C-1]
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.
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?
If 'Cp' and 'Cv' are molar specific heats of an ideal gas at constant pressure and volume respectively. If 'λ' is the ratio of two specific heats and 'R' is universal gas constant then 'Cp' is equal to ______.
Specific heat capacity C = ______.
Match the following:
| Column A | Column B | ||
| 1. | Specific heat capacity of water | a. | 0°C |
| 2. | Latent heat of fusion of ice | b. | 2260 J/g |
| 3. | Latent heat of vaporization of water | c. | 100°C |
| 4. | The melting point of iced | d. | 4.2 J/g°C |
| 5. | The boiling point of water | e. | 336 J/g |
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.
Prove the Mayer's relation `C_p - C _v = R/J`
A 0.2 kg metal at 150°C is placed in a copper calorimeter (water equivalent 0.025 kg) with 150 cm³ water at 27°C. Final temperature is 40°C. Find the specific heat of the metal.
