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Q1. Wind blows due to

• 1) Physical features of land
• 2) Difference in air pressure
• 3) Unequal heating of earth
• 4) Different climate of different places

Solution

Wind blows due to unequal heating of earth.

Q2. What are essential conditions for development of thunderstorm?

• 1) Unequal heating of earth
• 2) Low air pressure
• 3) Both (A) & (B)
• 4) Presence of moisture

Solution

Conditions for development of thunderstorm are unequal heating of earth as well as presence of moisture.

Q3. Why the can gets distorted when hot water is poured into it?

Solution

As the hot water is poured into the can, some steam in the can condenses into water, reducing the amount of air inside it. The pressure inside the can decreases than the pressure exerted by the air from outside the can. As a result, the can gets compressed.

Q4. What is atmospheric pressure?

Solution

Atmospheric pressure is the air pressure which is exerted by the weight of air present in the atmosphere.

Q5. Anemometer indicates direction of wind.

• 1) False
• 2) True

Solution

Anemometer measures the speed of wind.

Q6. A violent storm with a column of rapidly rotating winds, having the appearance of a dark, funnel-shaped cloud that reaches the sky to the ground is called

• 1) Cyclone
• 2) Tornado
• 3) Earthquake
• 4) Thunderstorm

Solution

A violent storm with a column of rapidly rotating winds, having the appearance of a dark, funnel-shaped cloud that reaches the sky to the ground is called tornado.

Q7. When does a tornado develop?

• 1) When moist hot air rises & falls down as rain.
• 2) Both (A) & (B)
• 3) When rising hot air meets horizontal cool current
• 4) Storm that develops over sea

Solution

When rising hot air meets horizontal cool current.

Q8. What happens when air gets heated up?

• 1) Air molecules move far away
• 2) It rises up as it becomes light
• 3) Air expands
• 4) All of these

Solution

All of these

Q9. Air expands on heating and contracts on cooling.

• 1) False
• 2) True

Solution

True

Q10. (i) Why monsoon winds are known as seasonal winds?(ii) Why sea breeze blow during day?

Solution

(i) During the months of June to September due to high temperature, sea breeze blows from sea to land which carry high amount of moisture and cause rainfall in India. So, these are known as summer monsoon winds. (ii) Sea breeze blows during day because a.Land gets heated quickly so low pressure develops over land. b.Water takes time to heat so high pressure is over the water.

Q11. Why winds blow in easterly direction?

• 1) Because earth is tilted
• 2) Earth rotates from west to east
• 3) None of these
• 4) Due to revolution of earth around sun

Solution

Earth rotates from west to east.

Q12. Which hurricane affected eastern U.S in august 2005?

• 1) Rita 
• 2) Hugo
• 3) Katrina
• 4) None of these

Solution

Katrina affected eastern U.S in august 2005.

Q13. When is a storm expected?

Solution

When the pressure difference between two areas is very high then cool air rushes at very high speed towards low pressure area. In such a condition storm is expected.

Q14. A cyclone alert or cyclone watch is issued __________ hours in advance of any expected storm and a cyclone warning is issued _______ hours in advance.

Solution

A cyclone alert or cyclone watch is issued 48 hours in advance of any expected storm and a cyclone warning is issued 24 hours in advance.

Q15. Why land breeze blows during night?

Solution

Land breeze blows during night because a.Land looses heat quickly and cools down so there is high air pressure on land. b.Water retains heat for a longer time so low air pressure develops over land.

Q16. Why both polar winds and westerlies blow towards 60 degree N and 60 degree S latitude?

Solution

Polar winds blow from high pressure on poles to temperate region as there is low air pressure. Westerlies are the hot winds which rise from equator and get cools and come down and then blow towards temperate region. So, both polar winds and westerlies blow towards 60 degree N and 60 degree S latitude.

Q17. Explain formation of thunderstorms in your words?

Solution

Due to unequal heating of earth surface, air gets heated up soon due to which the following sequence of events takes place: a. Air pressure decreases. b. Hot moist air rises up. c. Condensation occurs and clouds are formed. d. More heat is released as a result clouds rise up. e. Water droplets become heavy and fall on earth as rain. f. Hot air also gets cool and comes down speedily and warm air rises. This is accompanied by thunder and lightning.

Q18. What is the main cause for the development of storm?

Solution

The main cause for the development of storm is unequal heating of the surface of earth.

Q19. List any one basic difference between tornado and cyclone.

Solution

One basic difference between tornado and cyclone is that tornado develops over land while cyclone develops over sea.

Q20. Why is cyclone the most destructive natural calamity?

Solution

Cyclone is the most destructive natural calamity because it last longer and affects a wider area.

Q21. ____________ indicates the direction of wind.

Solution

Wind vane indicates the direction of wind.

Q22. Why tornadoes are also known waterspouts?

Solution

When tornadoes develop over sea, it sucks up a huge column of water and are known as waterspouts.

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