Advertisements
Advertisements
प्रश्न
Explain, why does a wise farmer water his fields, if forecast is forst?
Advertisements
उत्तर
The frost can seriously damage the leaves and fruit of plants. When a farmer waters his fields, during, night, this water gives large amount of heat energy, because 1 g of water will liberate 4.2 J of energy for every 1°C fall in temperature. Thus, the air around the field is saturated with heat energy and its temperature does not fall below 0°C. Thus, no frost is formed.
संबंधित प्रश्न
Water in lakes and ponds do not freeze at once in cold countries. Give a reason is support of your answer.
What do you mean by the following statement?
The heat capacity of a body is 50 JK-1?
Why do bottled soft drinks get cooled, more quickly by the ice cubes than by the iced water, both at 0℃?
How much heat energy is released when 5.0 g of water at 20℃ changes into ice at 0℃? Take specific heat capacity of water = 4.2 J g-1 K-1, Specific latent heat of fusion of ice = 336 J g-1.
Solve the following problems:
Equal heat is given to two objects A and B of mass 1 g. Temperature of A increases by 3°C and B by 5°C. Which object has more specific heat? And by what factor?
A piece of iron of mass 2.0 kg has a heat capacity of 966 J K-1. Find its specific heat capacity in S.I unit.
Explain, Why is it advisabile to pour cold water over burns, caused on human body, by hot solids?
Two cylinders of equal height and radius are made of copper and aluminum. Which of them conducts heat faster?
Two blocks P and Q of different metals having their mass in the ratio 2 : 1 are given same amount of heat. Their temperature rises by same amount. Compare their specific heat capacities.
Which method is used to determine the specific heat capacity of both solids and liquids by mixing a substance of unknown specific heat with water?
