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प्रश्न
State factors on which the amount of heat radiated by a body depends.
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
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?
Heat energy is supplied at a constant rate to 100g of ice at 0 °C. The ice is converted into water at 0° C in 2 minutes. How much time will be required to raise the temperature of water from 0 °C to 20 °C? [Given: sp. heat capacity of water = 4.2 J g-1 °C-1, sp. latent heat of ice = 336 J g-1].
Name the S.I. unit of heat.
Write the approximate value of specific heat capacity of water in S.I. unit.
In an experiment to determine the specific heat capacity of a solid following operations were
made:
Mass of calorimeter + stirrer = x kg
Mass of water = y kg
Initial temperature of water t1℃
Mass of solid = z kg
Temperature of solid = t2 ℃
Temperature of mixture = t ℃
Specific heat capacity of calorimeter and water are c1 and c2 respectively. Express the specific
heat capacity c of the solid in terms of the above data.
The specific heat capacity of water is :
Name two green house gases ?
State the effect of enhancement of green house effect.
How will climate changes affect the various animal species?
Study the following procedure and answer the questions below:
1. Take 3 spheres of iron, copper and lead of equal mass.
2. Put all the 3 spheres in boiling water in a beaker for some time.
3. Take 3 spheres out of the water. Put them immediately on a thick slab of wax.
4. Note, the depth that each sphere goes into the wax.
i) Which property of substance can be studied with this procedure?
ii) Describe that property in minimum words.
iii) Explain the rule of heat exchange with this property.
In Regnault's apparatus for measuring specific heat capacity of a solid, there is an inlet and an outlet in the steam chamber. The inlet is near the top and the outlet is near the bottom. Why is it better than the opposite choice where the inlet is near the bottom and the outlet is near the top?
The substances like water which have ........... Heat capacity warm up more slowly than substances like iron which have .......... heat capacity.
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?
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?
Describe a method to determine the specific heat capacity of a solid (say, a piece of copper).
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?
Define specific heat capacity.
What is specific heat capacity?
Numerical Problem.
How much heat energy is required to change 2 kg of ice at 0°C into water at 20°C? (Specific latent heat of fusion of water = 3,34,000 J/kg, Specific heat capacity of water = 4200 JKg–1K–1).
Derive Meyer’s relation for an ideal gas.
On supplying 100 µC of charge to a conductor, its potential rises by 5 V then capacity of the conductor is ______.
Two metals A and B have specific heat capacities in the ratio 2:3. If they are supplied same amount of heat then
Which metal piece will have greater mass if the rise in temperature is the same for both metals?
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.
Calculate the amount of heat energy required to raise the temperature of 200 g of copper from 20°C to 70°C. Specific heat capacity of copper = 390 J kg-1 K-1.
