Understanding the Cooling Effect of Water
We feel cool after applying water on our skin in summer primarily because of the process of evaporation.
The Science of Evaporation
- Evaporation Process: When water is applied to the skin, it starts to evaporate, turning from a liquid into water vapor (a gas).
- Heat Absorption: This phase change from liquid to gas requires energy. The water absorbs this necessary energy in the form of heat.
- Source of Heat: The heat is drawn directly from the skin surface.
- Cooling Sensation: As the water absorbs heat from the skin to evaporate, it lowers the skin's temperature, creating a cooling effect.
Why Other Options Are Incorrect
- Option 2: Water aids evaporation (which cools), it doesn't reduce sweat formation in a way that retains heat; evaporation *is* the cooling mechanism.
- Option 3: Water absorbs some sunlight, but the dominant cooling effect comes from evaporation, not from reducing heat absorption from sunlight.
- Option 4: Condensation is the process where water vapor turns into liquid, releasing heat. This would warm the skin, not cool it.
Therefore, the primary reason for feeling cool is the heat absorbed by water during evaporation from the skin surface.
Similar Questions
- The body of the cooking vessel is of metal and handles are of plastic because ______.
- ______ is the unit of thermal conductivity.
- The heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V is
- An electric iron of resistance 20 ohm takes a current of 5 A. The heat flow in 30 s is:
- The volume of a given amount of water ______ when its temperature is increased from \(0^\circ\text{C}\) to \(4^\circ\text{C}\).
- The SI unit of heat energy transferred is expressed in ______.
Which statement correctly differentiates heat and temperature based on their SI units?
Which of the following is NOT an effect of heat?
Which statement correctly defines the temperature of a body?
The resistance of a metal rod depends on all of the following, except ______.
Important Questions from Heat and Transfer
In summer season, the top and outer surface of the house are painted white because:
What is the heat released by a heating filament rated 24 W when it is kept on for 6 seconds?
On a hot summer afternoon, the tent made up of fabric will be preferred as white colour is:
The coil of wire used in electric heaters is called a/an________.
Transfer of heat by convection can take place in
