Winds, Storms, and Cyclones | Science | Chapter 8 | Class 7th | Questions and Answers |

JANDKNCERT | Science | Class 7th |

Winds, Storms, and Cyclones | Science | Chapter 8 | Class 7th | Questions and Answers |

 

Chapter 8: Winds, Storms, and Cyclones

EXERCISES

Q1. Fill the missing word in the blank spaces in the following statements:

(a) Wind is __________ air.

(b) Winds are generated due to __________ heating on the earth.

(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.

(d) Air moves from a region of __________ pressure to a region of __________pressure.

Ans.

(a) Wind is moving air.

(b) Winds are generated due to uneven heating on the earth.

(c) Near the earth’s surface, warm air rises up whereas cooler air comes down.

(d) Air moves from a region of high pressure to a region of low pressure.

 

Q2. Suggest two methods to find out wind direction at a given place.

Ans.

Method 1: One of the easiest methods to find the direction of the wind is to burn a candle and see the direction of the burning flame. The direction of the burning flame will show us the direction of the wind.

Method 2: Movement of the leaves of a tree or the direction in which the dry leaves move.

 

Q3. State two experiences that made you think that air exerts pressure (other than those given in the text).

Ans. Movement of the windmill and leaves of trees shows that air exerts pressure. If we continue to fill the balloon with the air it will burst. This shows that air exerts pressure.

 

Q4. You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.

Ans. Ventilation keeps the rooms of a house cool. We know that warm air rises up when a cool breeze replaces it, so if there is no ventilation in a house, the warm air will remain there that will keep the rooms warm. Moreover ventilators allow the fresh to enter the room that is good for health, so it is good to buy a house with ventilators.

 

Q5. Explain why holes are made in hanging banners and hoardings.

Ans. Air exerts pressure, and if there will be no holes in banners and hoardings, this air pressure will not allow the banner to stand fixed in a place. That is why holes are made in hanging banners and hoardings because the air passes through these holes and makes it stand at a fixed place.

 

Q6. How will you help your neighbours in case a cyclone approaches your village/town?

Ans. First of all, we will convince our neighbors to leave the place and shift to a safer place. Then we will try to shift their belongings, such as household goods, domestic animals, pets, vehicles, and other important things to a safer place. At last, we will call the emergency services for help.

 

Q7. What planning is required in advance to deal with the situation created by a cyclone?

Ans. Following planning is required in advance to deal with the situation created by a cyclone:

·     A cyclone forecast and warning service equipment.

·     Equipment for rapid communication of warning to the government agencies, the ports, fishermen, ships, and to the general public

·     Construction of cyclone shelters in the cyclone-prone areas and administrative arrangements for moving people fast to safer places.

·     Keep ready the phone numbers of all the emergency services.

·     Keep drinking water and food in airtight and waterproof bags.

 

Also Read: More about your body structure

 

Q8. Which one of the following places is unlikely to be affected by a cyclone?

(i) Chennai

(ii) Mangaluru (Mangalore)

(iii) Amritsar

(iv) Puri

Ans. (iii) Amritsar

 

Q9. Which of the statements given below is correct?

(i) In winter the winds flow from the land to the ocean.

(ii) In summer the winds flow from the land towards the ocean.

(iii) A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.

(iv) The coastline of India is not vulnerable to cyclones.

Ans. (i) In winter the winds flow from the land to the ocean.

 

Points to Remember

Ø  Moving air is called the Wind.

Ø  Increased wind speed is, indeed, accompanied by reduced air pressure.

Ø  Air moves from the region where the air pressure is high to the region where the air pressure is low.

Ø  Wind currents are generated due to the uneven heating on the earth.

Ø  The word monsoon is derived from the Arabic word ‘Mausam which means ‘season’.

Ø  Cyclones are caused by the difference in the high-speed winds and air pressure.