Chapter 8: Winds, Storms and Cyclones

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Chapter 8: Winds, Storms and Cyclones

  Class VII

  Multiple Choice Questions

Question 1

A fire alarm usually detects smoke in case of fire. Where should such an alarm be placed in a room?

(a) Near the door

(b) On the floor

(c) On any wall

(d) On the ceiling

Answer 1

(d)

Question 2

 

Four schematic diagrams are shown in Figure 8.1 to depict the direction of sea breeze. Which of them gives the correct direction?

Answer 2

(c)

Question 3

 

Figure 8.2 shows a child blowing air with a straw near the opening of another straw which has its other end in a soft drink bottle. It was observed that the level of the soft drink in the straw rises up as soon as air is blown over its open end. Which one of the following best explains the reason for rise in level of the drink?

(a) Blowing of air decreases pressure over the opening of the straw.

(b) The straw of the soft drink bottle collapses when air is blown over its open end.

(c) Blowing of air warms up the air inside the straw.

(d) Blowing of air increases the pressure on the surface of soft drink in the bottle.

Answer 3

(a)

Question 4

Following are precautions one must take in case a storm is accompanied by lightning.

(i) Do not take shelter under a tree.

(ii) Do not take shelter under an umbrella with a metallic end.

(iii) Do not take shelter in open garages, storage sheds, etc.

(iv) Do not take shelter in a bus in the open.

Which one of these is not correct?

(a) (i) (b) (ii)

(c) (iii) (d) (iv)

Answer 4

(d)

Question 5

Which of the following place is most likely to be affected by a cyclone?

(a) Mumbai

(b) Puri

(c) Goa

(d) Porbandar

Answer 5

(b)

Question 6

A curtain is hanging at the entrance of a room. A long corridor runs at right angles to the door, that is parallel to the curtain. If a strong wind blows along the corridor, the curtain will

(a) get pushed inside the room.

(b) get pushed outside the room.

(c) get collected towards one end/swirled.

(d) remain unaffected.

Answer 6

(b)  

Very Short Answer Questions

Question 7

Why is Chandigarh unlikely to be affected by a cyclone?

Answer 7

As it is not near to the sea/ocean.

Question 8

Name the ocean which is mainly responsible to bring rain bearing monsoon winds to Kerala coast in June every year?

Answer 8

Indian Ocean

Question 9

Fill in the blanks.

(i) Air around us exerts __________ .

(ii) The moving air is called _________ .

(iii) The main cause of wind movement is uneven ___________ on the earth.

(iv) High speed wind can cause cyclone in regions of ___________ pressure.

Answer 9

(i) pressure

(ii) wind

(iii) heating

(iv) low

Question 10

State whether the following statements are True or False:

(i) If wind flows from land to the ocean, then it is daytime.

(ii) A very high pressure system, with very high speed wind surrounding it forms a cyclone.

(iii) The coast line of India is not vulnerable to cyclones.

(iv) Warm air is lighter than cool air.

Answer 10

(i) False

(ii) False

(iii) False

(iv) True

Question 11

To expel hot air out of the kitchen, ‘A’ has an exhaust fan fitted on the window of her kitchen and ‘B’ has a similar exhaust fan fitted on the wall near the ceiling of her kitchen.

Which of the exhaust fan will expel the hot air more effectively? Explain why?

Answer 11

B’s exhaust fan will expel the hot air more effectively because

hot air rises up and her fan is at greater height than A’s.

Question 12

Why is it advisable not to shut all the doors and windows during a storm?

Answer 12

To avoid the roof getting blown away due to the low pressure

created by heavy wind.

Question 13

A flat in Mumbai with a balcony facing the sea has some clothes hung on a clothes line in the balcony. Towards which direction the clothes will be blown in the afternoon? Explain.

Answer 13

The clothes will be blown towards the house due to sea breeze

blowing towards the land.

Question 14

Figure 8.3 shows a diagrammatic representation of trees in the afternoon along a sea coast. State on which side is the sea; A or B? Give reasons for your choice.

Answer 14

B as the wind is blowing from the sea to the land.

Question 15

A flag mounted on a flag post near the sea coast flutters in the direction of sea. At what time of the day does this happen – at midnight or in the afternoon?

Answer 15

Midnight.

Short Answer Questions

Question 16

Match Column I with Column II. There can be more than one match.

Answer 16

(a) (ii) and (iv)

(b) (i) and (iii)

Question 17

Paheli kept an empty bottle made of plastic inside a refrigerator. After few hours, when she opened the refrigerator she found the bottle had collapsed. Explain the possible reason.

Answer 17

The air inside the bottle contracts due to low temperature hence

the bottle collapses due to the outside pressure.

Question 18

When strong/high speed wind blows, an umbrella held upright at times gets upturned. Explain the reason.

Answer 18

High speed wind passing over the umbrella creates low

pressure. Therefore the umbrella upturns.

Question 19

Suggest some precautions to be taken to prevent the roof of a tin sheet from flying away during a fierce wind storm.

Answer 19

(i) Put heavy stones on it.

(ii) Screw it tight.

Long Answer Questions

Question 20

Describe an activity to demonstrate that warm air is lighter than cool air.

Answer 20

Activity 8.6, Science Textbook, Class VII, NCERT or students

may design any other activity and the teacher may verify the

validity of the same.

Question 21

The picture in Figure 8.4 shows tree line along the sea coast on an island near the equator. As shown, the tree tops are permanently bent in one direction. Are the trees bent towards the sea or away from it? Explain.

 

Answer 21

In the day time wind blows from sea to land. This sea breeze

makes the trees to bend towards the land.

Question 22

Identify the names of six natural phenomena from the following word diagram given as Figure 8.5.

 

 

Answer 22