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प्रश्न
How can you experimentally prove water is a bad conductor of heat? How is it possible to heat water easily while cooking?
उत्तर
Take a glass tube and drop an ice cube wrapped in wire gauze in it.
Now fill 3/4th of this tube with water and place it above the burner as shown in the figure.
You can observe that the water boils at the edge and the ice present in the bottom of the tube has not melted indicating that heat has not reached the bottom where the ice cube is present. This proves that water is a bad conductor of heat.
It is easy to heat water easily or quickly while cooking. This is because, while cooking the vessel or pan is usually covered with a lid.
This leads to three things;
- Radiation from the hot water is reflected back into the pan rather than being emitted
- Free convection is effectively eliminated, and
- Evaporative cooling’ is also eliminated.
This in turn allows the water to be heated more easily.
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संबंधित प्रश्न
Match the following.
| Conduction | Liquid |
| Convection | Gas to liquid |
| Radiation | Solid to gas |
| Sublimation | gas |
| Condensation | Solid |
What is conduction?
Liquids and gases are generally ______ conductors of heat.
Define conduction.
In conduction, heat flows from ______.
Mud houses are cooler in summer and warmer in winter because ______.
When two objects are in thermal contact, the heat is transferred by ______.
Match the following
| 1. | Convection | a. | liquids and gases |
| 2. | Convection | b. | Poor conductor |
| 3. | Radiation | c. | Solids |
| 4. | Snow | d. | Vacuum |
Why do we wear woolen clothes in winter?
Give some practical applications of conduction in daily life.
