Factors Affecting Evaporation

Q.

How does the water kept in an earthen pot (matka) become cool during summer?

Q.

How does the water keep in an earthen pot become cool during summer?

Q.

What are the factors affecting evaporation ? [5 MARKS]

Q.

Water in a dish evaporates faster than in a bottle. Give reasons

Q.

Why washed clothes take longer time to dry in rainy season ?

Q.

How does water in an earthen pot become cool during summer?

Q.

Water stored in an earthen vessel becomes cool. Explain.

Q.

Explain how droplets are formed.

Q.

Give reason for the increase in rate of evaporation of a liquid when

(a) air is blown above the liquid

(b) surface area of liquid is increased

(c) temperature of liquid is increased.

Q.

Select the correct alternative :

(a) In evaporation :

(i) all molecules of liquid begin to escape out

(ii) only the molecules at the surface escape out

(iii) the temperature of the liquid rises by absorbing heat from surroundings.

(iv) the molecules get attracted within the liquid.

(b) The rate of evaporation of a liquid increases when :

(i) the temperature of liquid falls

(ii) the liquid is poured in a vessel of less surface area

(iii) air is blown above the surface of the liquid

(iv) humidity increases.

(c) During boiling or vaporization :

(i) all molecules take part

(ii) temperature rises

(iii) no heat is absorbed

(iv) the average kinetic energy of molecules increases.

(d) The boiling point of a liquid is increased by :

(i) increasing the volume of liquid

(ii) increasing the pressure on the liquid.

(iii) adding ice to the liquid

(iv) decreasing pressure on the liquid.

(e) Two rods A and B of the same metal, but of length 1 m and 2 m respectively, are heated from $0^{\circ }$ to ${100}^{\circ }C$. Then :

(i) both the rods A and B elongate the same

(ii) the rod A elongates more than the rod B

(iii) the rod B elongates more than the rod A

(iv) the rod A elongates, but the rod B contracts.

(f) Two rods A and B of the same metal, same length, but one solid and the other hollow, are heated to the same rise in temperature. Then :

(i) the solid rod A expands more than the hollow rod B

(ii) the hollow rod B expands more than the solid rod A

(iii) the hollow rod B contracts, but the solid rod A expands

(iv) both the rods A and B expand the same.

(g) A given volume of alcohol and the same volume of water are heated from the room temperature to the same temperature then :

(i) alcohol contracts, but water expands

(ii) water contracts, but alcohol expands

(iii) water expands more than alcohol

(iv) alcohol expands more than water.

(h) The increase in length of a metal rod depends on :

(i) the initial length of the rod only

(ii) the rise in temperature only

(iii) the material of rod only

(iv)all the above three factors.

(i) The correct statement is :

(i) Iron rims are cooled before they are placed on the cart wheels.

(ii) A glass stopper gets tightened on warming the neck of the bottle.

(iii) Telephone wires sag in winter, but become tight in summer.

(iv) A little space is left between two rails on a railway track.

Q.

Which of the following help in lowering the melting point of ice and why?

The options are :-

Sugar

Salt

Milk

Water

Q. Comment on the statement ' evaporation is a surface phenomenon '

Q.

Name the process responsible for cooling of water kept in earthen pot during summers.

Q.

Why does a papad when suspended in boiling oil become crispier??

Q.

Why does our palm feel cold when we put some perfume on it?

Q. One litre of water is kept in 5 different bowls with different surface areas at the top surface. Choose the bowl in which the water will evaporate fastest.

1. Bowl with top surface area = $200$ m${}^2$
2. Bowl with top surface area = $350$ m${}^2$
3. Bowl with top surface area = $100$ m${}^2$
4. Bowl with top surface area = $50$ m${}^2$

Q.

Name the process responsible for cooling of water kept in an earthen pot during summer.

Q. During summer season, water kept in an earthen pot becomes cool because of the phenomenon of :

1. diffusion
2. transpiration
3. osmosis
4. evaporation

Q.

Four containers with an equal volume of water were kept in different conditions. The rate of evaporation will be maximum in the container which is kept :

1. under a tree

2. in the open area

3. in the room

4. below a moving fan in the room

Q. The rate of evaporation decreases with an increase in _________.

1. humidity
2. temperature
3. wind speed
4. surface area

Q.

Which condition out of the following will increase the evaporation of water ?

1. Increase in temperature of water

2. Decrease in temperature of water

3. Less exposed surface area of water

4. Adding common salt to water

Q.

How does liquid evaporates ?

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Q.

Strength of induced current is increased when

1. Speed of conductor decreases

2. Magnetic field strength decreases

3. Magnetic field strength increases

4. Number of turns in coil decreases

Q. Give three factors that affect evaporation with an explanation. [3 MARKS]

Q. In which case evaporation of water will be faster?

1. Near the sea
2. Away from the sea
3. In the middle of the sea
4. Evaporation does not depend upon distance from sea

Q. Which condition out of the following will increase the evaporation of water?

1. Adding common salt to water
2. Less exposed surface area of water
3. Increase in temperature of water
4. Decrease in temperature of water

Q.

Discuss the factors that affect evaporation?

Q.

Rate of evaporation increases with:

1. Increase of surface area.

2. Increase of temperature.

3. An increase in wind speed.

4. All the options are correct.

Q.

The rate of evaporation increases with__.

1. Increase of surface area.

2. Increase of temperature.

3. An increase in wind speed.

4. All the options are correct.

Q. Identify the factors that affect the process of evaporation.

1. Temperature
2. Surface area
3. Humidity
4. Density