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प्रश्न
Explain, why does a wise farmer water his fields, if forecast is forst?
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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
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 :
Figure shows a paddle wheel coupled to a mass of 12 kg through fixed frictionless pulleys. The paddle is immersed in a liquid of heat capacity 4200 J K−1 kept in an adiabatic container. Consider a time interval in which the 12 kg block falls slowly through 70 cm. (a) How much heat is given to the liquid? (b) How much work is done on the liquid? (c) Calculate the rise in the temperature of the liquid neglecting the heat capacity of the container and the paddle.
Fill in the following blank using suitable word:
SI unit of heat is .........
A. hot solid of mass 60 g at 100°C is placed in 150 g of water at 20° C. The final steady temperature recorded is 25°C. Calculate the specific heat capacity of the solid. [Specific heat capacity of water = 4200 J kg-1 °C-1]
What is specific heat capacity?
Express the change in internal energy in terms of molar specific heat capacity.
Which of the following substances (A, B and C) has the highest specific beat?
Two cylinders of equal height and radius are made of copper and aluminum. Which of them conducts heat faster?
Match the columns:
| Column ‘A’ | Column ‘B’ |
| The SI unit of specific heat capacity | (a) Jkg−1°C−1 |
| (b) kg/m3 | |
| (c) calorie |
