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प्रश्न
Read this activity and answer the following questions.
- Take three spheres of iron, copper and lead. the lead of equal mass.
- Put all the three spheres in boiling water in the beaker for some time.
- Take the three spheres out of the water.
- All the spheres will be at a temperature 100 °C.
- Put them immediately on the thick slab of wax.
- Note, the depth that each of the sphere goes into the wax.
Questions:
- Which property is determined from this activity?
- Give name to that property.
- Explain the term principal of heat exchange with the help of this activity.
उत्तर
- Property which determines the amount of heat absorbed by a sphere is different for the three spheres is ascertain from this activity.
- This property is called the specific heat capacity.
- The sphere that absorbs more heat from water supplies more heat to wax causing more melting of wax and going deeper in wax obeying the principle of heat exchange which states that; In an isolated system, Heat lost by hot object = Heat gained by cold object.
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संबंधित प्रश्न
During the phase change does the average kinetic energy of the molecules of the substance increase?
Two metallic blocks P and Q of masses in ratio 2: 1 are given the same amount of heat. If their temperature rise by the same amount, compare their specific heat capacities.
A heater of power P watt raises the temperature of m kg of a liquid by Δt K in time t s. Express
the specific heat capacity of liquid in terms of above data.
How will global warming disturb the ecological balance?
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.
Indian style of cooling drinking water is to keep it in a pitcher having porous walls. Water comes to the outer surface very slowly and evaporates. Most of energy needed for evaporation is taken from the water itself and the water is cooled down. Assume that a pitcher contains 10 kg of water and 0.2 g of water comes out per second. Assuming no backward heat transfer from the atmosphere to the water, calculate the time in which the temperature decrease by 5°C. Specific heat capacity of water = 4200 J kg−1 °C−1 and latent heat of vaporization of water = 2.27 × 106 J kg−1.
What are other units of heat? Name and define them.
Write two advantages of high specific heat capacity of water.
Explain, Why is it advisabile to pour cold water over burns, caused on human body, by hot solids?
Give two reasons as to why copper is preferred over other metals for making calorimeters.
State factors on which the amount of heat radiated by a body depends.
Which of the substances P, Q, or R has the lowest specific heat? The temperature v/s time graph is shown ______.
At same temperature and pressure of an ideal gas, ____________.
The specific heat capacity of water is ______.
Two cylinders of equal height and radius are made of copper and aluminum. Which of them conducts heat faster?
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 |
Observe the following diagram and answer the questions given below:
Specific heat capacity of metals
- Which element has maximum specific heat capacity? Justify.
- Which element has minimum specific heat capacity? Justify.
- Define specific heat of object.
Prove the Mayer's relation `C_p - C _v = R/J`
