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प्रश्न
The cold object the hot object enclosed in one box of heat-resistant material.
- What changes will occur in the two objects when temperature flows from those objects?
- Which principle can show that the energy exchange takes place between two objects only when kept in isolated system?
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उत्तर
1. Temperature of cold object increases due to gain of heat energy.
2. At the same time, temperature of hot object decreases due to loss of heat energy.
3. The process of heat exchange continues till both the objects acquire the same temperature.- Principle of heat exchange can show that the energy exchange takes place between two objects only when kept in isolated system.
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संबंधित प्रश्न
A mass m1 of a substance of specific heat capacity c1 at temperature t1 is mixed with a mass m2 of other substance of specific heat capacity c2 at a lower temperature t2. Deduce the expression for the temperature t of the mixture. State the assumption made, if any.
Name three fossil fuels that emit carbon dioxide into the atmosphere ?
How will global warming disturb the ecological balance?
How will you prove experimentally that different substances have different specific heat capacities?
Give one example where high specific heat capacity of water is used as cooling.
The substances like water which have ........... Heat capacity warm up more slowly than substances like iron which have .......... heat capacity.
What change in heat energy occurs when lead at its melting point
solidifies without change in the temperature?
State, with reason, which of the two, boiling water or steam both at 100°C will produce more severe burns.
A liquid X has specific heat capacity higher than the liquid Y. Which liquid is useful as coolant in car radiators.
Explain, why water is considered as best liquid for quenching thirst?
Describe a method to determine the specific heat capacity of a solid (say, a piece of copper).
Explain how heat capacity of a solid can be determined by the method of mixture.
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.
Numerical Problem.
What is the heat in joules required to raise the temperature of 25 grams of water from 0°C to 100°C? What is the heat in Calories? (Specific heat of water = `(4.18"J")/("g"°"C")`
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]
When two kilocalories of heat are supplied to a system, the internal energy of the system increases by 5030 J and the work done by the gas against the external pressure is 3350 J. Calculate J, the mechanical equivalent of heat.
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.
