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प्रश्न
Explain the meaning of greenhouse effect.
उत्तर
The phenomenon of the trapping of infrared radiations of long wave length being radiated to space by greenhouse gases like carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) to keep the environment warm at the planet’s surface and the lower atmosphere is called greenhouse effect.
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संबंधित प्रश्न
State any two measures to minimize the impact of global warming.
What do you understand by the term latent heat?
- Which requires more heat: 1 g ice at 0℃ or 1 g water at 0℃ to raise its temperature to 10℃?
- Explain your answer in part (a).
Explain the following:
The surrounding become pleasantly warm when water in a lake starts freezing in cold countries.
Explain the following:
The heat supplied to a substance during it change of state, does not cause any rise in its temperature.
A refrigerator converts 100g of water at 20℃ to ice at – 10℃ in 73.5 min. Calculate the average rate of heat extraction in watt. The specific heat capacity of water is 4.2 J kg-1 K-1, specific latent heat of ice is 336 J g-1 and the specific heat capacity of ice is 2.1 J kg-1 K-1.
Explain the following temperature vs time graph.
Define the following terms:
(i) Latent heat,
(ii) Latent heat of fusion of ice.
What is the name given to the energy absorbed during a phase change?
Explain why water is used in hot water bottles for fomentation and also as a universal coolant.
Give one consequence of the high specific latent heat of fusion of ice.
1 kg of water is contained in a 1.25 kW kettle. Assuming specific heat capacity of water = 4.2 J/g °C and specific latent heat of vaporization = 2260 J/g, calculate:
(i) the time taken for the temperature of water to rise from 25°C to its boiling point,
(ii) the mass of water which evaporates per minute from the boiling water.
When ice is converted into water : constant temperature : : before the water evaporates : _______
Find the odd one out and give its explanation.
Define specific latent heat capacity
Specific latent heat of a substance ______.
The diagram below shows a cooling curve for a substance:
- State the temperatures at which the substance condenses.
- The temperature range in which the substance is in liquid state.
- Why do we prefer ice to ice-cold water for cooling a drink?
