Tag: heat, internal energy and work

Questions Related to heat, internal energy and work

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change


Which is the final step of a water cycling driving small turbines before it is fed back into the primary pool?

  1. Evaporation

  2. Fermentation

  3. Sublimation

  4. Vaporisation

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Evaporation is the final step of a water cycling driving small turbines before it is fed back into the primary pool. Water vapours are moving in the pipe at high speed under pressure exposed to turbine; which makes turbine rotate; left water vapour again condenses and go back in liquid state.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

What is not true about evaporation?

  1. Greater the surface area of the liquid, the quicker is the evaporation

  2. Evaporation produces cooling

  3. Evaporation takes place at all the temperatures

  4. Evaporation is nothing but boiling at the highest temperature of the liquid

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Evaporization is the vaporization process of converting the liquid phase to vapour phase when surrounding temperature is more than liquid / water temperature.

It should not be confused with boiling as boiling means whole phase change from liquid to vapour at highest temperature.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Statement-1
Evaporation takes place from the surface of a liquid.
Statement-2
The molecules at the surface have less attractive energy than those inside the liquid.

  1. Statement-1 is true, Statement-2 is true and Statement-2 is the correct explanation for Statement- 1

  2. Statement-1 is true, Statement-2 is true but Statement-2 is not the correct explanation for Staement-1

  3. Statement-1 is true, Statement-2 is false.

  4. Statement-1 is false, Statement-2 is true.

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Evaporation is a surface phenomenon.
Particles present on the surface of a liquid only face attraction from one side (the side containing fluid particles) and surface tension. Where as particles inside the liquid would face attractive forces from all around, making it difficult for such particles to evaporate or escape.
Hence the statement is true, explanation is true and the explanation is the correct explanation for the statement.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Which of the following statement is wrong ?

  1. At room temperature evaporation of water is rapid as compared to ethanol

  2. Water is more viscous as compared to ethanol

  3. Liquid drops are spherical in shape

  4. Clothes are easily dried in dry day as compared to humid days

Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

A: At room temperature evaporation of ethanol is rapid as compared to water. Hence, A is incorrect. 

B: water is more viscous compared to ethanol, hence statement is true. 
C: liquid drops are spherical due to surface tension of liquid drop,hence statement is true.
D: Clothes are dried easily as it is less humid on dry day,hence statement is true