Category: Clas-7 Geo Ch. 6 to 9

1. What is the climate of the Sahara Desert?

The Sahara Desert has an extremely hot and dry climate. Days are very hot, while nights can become very cold. Rainfall is very little and irregular, and strong dusty winds are common.

2. What are the different names of the hot, dry and dusty winds that blow in the Sahara Desert?

The hot and dusty winds blowing in the Sahara Desert are known by different names such as Sirocco, Khamsin, and Harmattan in different regions.

3. Why has the Sahara region recently gained economic importance?

The Sahara region has gained economic importance because valuable minerals and resources such as petroleum, natural gas, iron, and uranium have been discovered there.

4. What is the meaning of the word Ladakh? Where is it located?

The word Ladakh means “Land of High Passes.” It is located in the northern part of India in the state of Ladakh, between the Karakoram Range and the Himalayas.

5. What kind of climate is found in Ladakh?

Ladakh has an extremely cold and dry climate. Winters are very cold with heavy snowfall, while summers are short and cool. Rainfall is very low.

1. What factors are responsible for extreme weather in Ladakh?

Ladakh experiences extreme weather due to its high altitude, which causes low air pressure and cold temperatures. It lies in a rain-shadow area, so it receives very little rainfall.

The region is surrounded by high mountains that block moisture-laden winds. Clear skies also cause strong heating during the day and rapid cooling at night, leading to large temperature differences.

2. What economic activities make Ladakh commercially viable?

The people of Ladakh practise agriculture in summer, growing crops such as barley and vegetables. Animal rearing, especially of yaks and sheep, is also important.

Tourism is a major source of income. Handicrafts, wool products, and trade with nearby regions also contribute to the economy.

3. What wildlife is found in Ladakh and how is it different from Sahara wildlife?

Ladakh has animals adapted to cold climates, such as snow leopard, wild goat, yak, and Tibetan antelope.

In contrast, the Sahara Desert has animals adapted to hot conditions, such as camels, desert foxes, and reptiles. Thus, wildlife differs according to climate.

4. How do people in the Sahara Desert lead a sustainable life?

People in the Sahara practise nomadic herding, trading, and oasis farming. They rear animals like camels, goats, and sheep and move from place to place in search of water and pasture.

Modern transport and mining activities have also provided employment, helping people maintain their livelihood.

5. How are people of the Sahara Desert affected by modernisation?

Modernisation has brought roads, transport, education, and medical facilities to desert regions. Many people now work in mining and oil industries instead of traditional occupations.

However, traditional nomadic lifestyles are gradually decreasing due to these changes.

1. The Bedouins and Tuaregs depend on animals.

Animals provide milk, meat, wool, and transport, which are essential for their survival.

2. The Bedouins and Tuaregs wear loose and light cotton clothes.

Loose clothes protect them from heat and allow air to circulate, keeping the body cool.

3. Mining is an important occupation in the Sahara Desert.

The region contains valuable minerals and oil resources, providing employment to many people.

4. Tourism in summer is the main livelihood in Ladakh.

During summer, tourists visit Ladakh for its scenic beauty and adventure tourism, providing income to local people.

1. c. 2. b. 3. d. 4. d. 5. a

1. Frigid, Temperate, Torrid
2. less 3. dense
4. inverse, increases, decreases
5. Meteorologists, dimatologists

1. T 2. T 3. T 4. T 5. F

1. c. 2. e. 3. a. 4. b. 5. d.

1. The heat zones are divided on the basis of the amount of heat received. Earth is divided into three heat zones – the torrid, temperate and frigid zones.

2. Latitude, altitude, distance from the sea, prevailing winds, ocean currents and slope of land are the factors that affect temperature.

3. If the wind is an onshore one, then there is heavy precipitation on the windward side of the highland or mountain which is known as relief rainfall. However, as this wind descends the leeward side of the mountain, it gets compressed and warmed, and so condensation does not take place. The leeward side, thus, hardly receives any precipitation and is called the rain-shadow area.

4. Air pressure decreases with an increase in altitude. As we go higher up into the atmosphere, there is a decrease in the density of air and so, air pressure decreases. On an average, the rate of decrease is 1 mb for every 10 m increase in height above sea level.

5. Doldrums are a region of very low atmospheric pressure where hot air rises due to intense heating from the Sun. Because the air rises vertically, there is very little horizontal (surface) wind movement, making the area calm and windless. Location: The doldrums are located near the Equator, within about 5° north and 5° south latitude. This area is also known as the Equatorial Low Pressure Belt.

1. Temperature and altitude are closely related. As we go higher above sea level, the temperature decreases. This happens because air near the Earth’s surface gets heat from the land, which is heated by the Sun. Higher up, the air becomes thinner and cannot hold much heat. On average, the temperature falls by about 1°C for every 165 metres increase in height. That is why hill stations and mountains are cooler than nearby plains even during summer. Thus, places at higher altitude are cooler than places at lower altitude.

2.The Coriolis effect is the change in the direction of winds and ocean currents due to the rotation of the Earth. Because the Earth rotates, winds do not move in straight lines but get deflected. Ferrel’s Law tells us the direction of this deflection: In the Northern Hemisphere, winds turn towards the right. In the Southern Hemisphere, winds turn towards the left. So, the Coriolis effect is the cause of wind deflection, while Ferrel’s Law explains how the direction changes in each hemisphere.

3. Air pressure is not the same everywhere on Earth. It changes due to differences in temperature. Warm air becomes light and rises, creating low-pressure areas, while cold air becomes heavy and sinks, forming high-pressure areas. Because of this, the Earth has four main pressure belts: i. Equatorial low-pressure belt ii. Subtropical high-pressure belts iii. Subpolar low-pressure belts iv. Polar high-pressure belts Winds blow from high-pressure areas to low-pressure areas, affecting climate and weather conditions.

4.Planetary winds, also called permanent winds, blow throughout the year in a fixed direction due to pressure belts. These include: i. Trade Winds ii. Westerlies iii. Polar Winds Periodic winds change their direction during different seasons or times of the day. The most important example is the Monsoon wind, which changes direction between summer and winter. Land breeze and sea breeze are also periodic winds. Both types of winds influence rainfall and climate in different regions.

5.Precipitation means water falling from clouds to the Earth’s surface after condensation of water vapour. The main types are: i. Rain – Water falls in liquid form when temperature is above freezing. ii. Snow – Ice crystals fall in very cold regions. iii. Sleet – A mixture of rain and snow or frozen raindrops. iv. Hail – Small balls of ice fall during strong thunderstorms. Precipitation is very important as it supplies water and supports life on Earth.