Longman Panorma Geography Solutions Solutions for Class 7 Social science Chapter 1 Our Environment are provided here with simple step-by-step explanations. These solutions for Our Environment are extremely popular among Class 7 students for Social science Our Environment Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Longman Panorma Geography Solutions Book of Class 7 Social science Chapter 1 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Longman Panorma Geography Solutions Solutions. All Longman Panorma Geography Solutions Solutions for class Class 7 Social science are prepared by experts and are 100% accurate.

Page No 37:

Question A.1:

What are the elements of weather and climate?

Answer:

The elements of weather and climate are as follows:

  • Temperature
  • Humidity
  • Pressure
  • Wind
  • Precipitation
  • Cloudiness
  • Sunshine

Page No 37:

Question A.2:

Why does temperature decrease with increasing latitude?

Answer:

The heating of the Earth's atmosphere is the result of absorption of solar radiation by the air. Near the surface of the Earth, the air is dense and it consists of water vapour and dust particles that absorb the heat. This results in the increase of temperature near the surface; however,  in the upper strata of atmosphere, air gets thinner and absorbs less heat. This is the reason why temperature decreases with increase in height.

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Question A.3:

Why are hill stations cooler than plains?

Answer:

Atmosphere of the Earth gets heated up as a result of heat radiated from the Earth's surface. The water vapour and dust particles present in the air absorb the heat and reflect it back into the atmosphere. The air is dense on the plains as compared to the hill stations where air is rare due to increased altitude. Therefore, atmosphere gets heated up more near the plains as compared to the hill stations.

Page No 37:

Question A.4:

Name the factors that affect atmospheric pressure.

Answer:

The factors that affect atmospheric pressure are as follows:

  1. Rotation of the Earth
  2. Altitude of a place
  3. Presence of water vapour
  4. Temperature of a place

Page No 37:

Question A.5:

What is wind? Name the instruments that are used to measure wind direction and wind speed.

Answer:

The horizontal movement of air from a region of high pressure to a region of low pressure is termed as wind. The instrument hat is used to measure the direction of wind is termed as wind vane. The instrument that is used to measure the speed of wind is known as anemometer.

Page No 37:

Question A.6:

Where and when did the super cyclone in India occur?

Answer:

The super cyclone occurred on the eastern coast of India, in Orissa in October 1999. It caused huge destruction of life and property in the coastal areas of Orissa.

Page No 37:

Question B.1:

Weather and climate

Answer:

Following table illustrates the difference between weather and climate:
 

Weather Climate
It is the atmospheric condition of a particular place or small area. It is the average atmospheric condition of a large area.
It is considered for a small period of time. It is considered for a long period of time.
It changes drastically in short duration of time. It remains almost constant and takes long time to change substantially.
Example: cloudy and humid Example: monsoon

Page No 37:

Question B.2:

Planetary winds and periodic winds

Answer:

The difference between planetary winds and periodic winds is as follows:
 

Planetary Winds Periodic Winds
These winds blow throughout the year across the Earth from a region of high pressure to low pressure. These winds change their direction after a particular time interval.
They do not change speed and direction frequently. They blow in one direction for a particular time period.
These winds are permanent throughout the year. They blow in a particular season only.
Examples: Trade winds, polar winds and Westerlies Example: Monsoon winds

Page No 37:

Question B.3:

Absolute humidity and relative humidity

Answer:

The amount of water vapour present in the atmosphere is known as humidity. Both absolute humidity and relative humidity are measures of water vapour. The difference between them is as follows:
 

Absolute Humidity Relative Humidity

Absolute humidity is a measure of actual amount of water vapour present in the air regardless of the temperature of the air.

Relative humidity is the percentage of maximum amount of water vapour that air can hold at any given temperature.
Absolute humidity does not take into account the amount of possible water vapour in the air Relative humidity accounts for maximum water vapour per unit/volume of air at a given temperature.
Absolute humidity is expressed in terms of units. Relative humidity is expressed in terms of percentage.

Page No 37:

Question C.1:

In Delhi summers are very hot and winters are very cold while Kochi experiences moderate summer and winters.

Answer:

Delhi experiences hot summers and cold winters due to its location in the dry interior of the Indian subcontinent. It is away from the moderating influence of coastal climate caused by humidity. It is also farther from the Equator than Kochi.
Kochi experiences moderate summers and winters due to its location in the lower latitude of the Indian subcontinent as well as its proximity to the sea. The sea provides a moderating influence to the surface by limiting the range of temperature.

Page No 37:

Question C.2:

Warm air exerts less pressure than cold air.

Answer:

With increase in temperature, air starts expanding and its density decreases. Being relatively less dense, the warm air becomes light and exerts less pressure. However, on the other hand, cold air is dense. Hence, it exerts more pressure as compared to warm air.

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Question C.3:

The equatorial region has low pressure.

Answer:

The equatorial region receives maximum amount of sunlight throughout the year. With the increase in temperature, the density of the air decreases. This light air exerts less pressure on the surface of the Earth, resulting in the formation of low pressure zone around the Equator.

Page No 37:

Question C.4:

High temperatures result in high humidity.

Answer:

Humidity can be defined as the amount of moisture present in the air. This moisture comes from the evaporation process. At places where temperature is high, the rate of evaporation increases and hence, the amount of humidity automatically rises.

Page No 37:

Question D.1:

Describe the heat zones of the earth with the help of a diagram.

Answer:

On the basis of the amount of heat received by a particular place, the Earth is divided into the following three heat zones:

1. Torrid zone: This is the hottest zone that extends from 0° to 23 1/2° N and S and receives the maximum amount of sunlight. The sunrays are perpendicular to this zone.

2. Temperate zone: In this zone, sunrays are slanting and hence, the zone is neither too cold nor too hot. The climate in this zone is moderate. It extends from 23 1/2° N to 66 1/2° N and 23 1/2° S to 66 1/2° S.

3. Frigid zone: Here, the sunrays are very inclined so this zone receives the minimum amount of sunlight. Hence, it remains the coldest zone. It extends from 66 1/2° N​ to North Pole and 66 1/2° S​ to South Pole, respectively.

Page No 37:

Question D.2:

Explain the three most important factors that influence the temperature of a place.

Answer:

The three most important factors that influence the temperature of a place are as follows:

1. Latitude: The vertical rays of the Sun concentrate on smaller area and,  therefore, increase its temperature. Since the vertical rays of the Sun heat the surface more as compared to the slanting rays, the Equator, which receives vertical rays, has higher temperature as compared to the poles, which receive slanting rays of the Sun. 

2. Altitude: There is a fall in temperature with increase of height because the rise in temperature is witnessed not just due to the direct sun rays but also through the heat absorbed by the air near the Earth's surface. Since the air is denser near the surface, the temperature  there is higher as compared to the hilly regions.
 
3. Distance from the sea: The sea breeze has a moderating influence on the seashore temperature as water heats and cools slowly. Places in the interior of the continents have greater contrasts in temperature.

Page No 37:

Question D.3:

What was the extent of destruction caused by the super cyclone of Orissa?

Answer:

The super cyclone caused huge destruction in Orissa and destroyed property and standing crops. The high velocity wind uprooted trees, electric poles and telephone poles that hindered normal life, including transport, communication and electricity supply of the state. The cyclone was accompanied by heavy rainfall that, in turn, brought about the flooding of low-lying areas of the state. Thousands of lives were taken away and millions were left homeless. This way, the super cyclone took heavy toll on the day-to-day functioning of the state.

Page No 37:

Question D.4:

What is condensation? What are its various forms?

Answer:

When air temperature falls, the water vapour in the saturated air condenses into liquid or solid state. This process is termed as condensation. There are several forms of condensation. Some of them are as follows:

1. Clouds: They are formed when water vapour condenses over dust particles and forms water droplets.
2. Dew: It is formed when the water vapour comes in contact with cool surfaces like grass and leaf and forms tiny water droplets.
3. Fog: It results from the condensation of water vapour near the surface of the Earth.
5. Frost: Dew occurring in the form of ice crystals is known as frost.
 

Page No 37:

Question E.1:

The amount of solar energy received by the earth is called

a. Radiation
b. solar radiation
c. terrestrial radiation
d. Insolation

Answer:

The correct answer is option (d).

Explanation: Since the Earth is very small in comparison to the Sun, it receives very less amount of sunlight. This amount of sunlight received by the Earth is referred as insolation.

Page No 37:

Question E.2:

The thermometer scale most commonly used in India is

a. Richter
b. Celsius
c. Fahrenheit
d. Kelvin

Answer:

The correct answer is option (b).

Explanation: Thermometer is an instrument used to measure temperature. There are two types of thermometer scales, that is, Fahrenheit and Celsius scale. However, in India, the most common type of thermometer is the Celsius scale thermometer. The freezing point of water on this scale is 0° Celsius and boiling point is 100° Celsius.
 

Page No 37:

Question E.3:

Which of the following is not a name given to tropical cyclones

a. Roaring Forties
b. Typhoons
c. Tornadoes
d. Hurricanes

Answer:

The correct answer is option (a).

Explanation: Typhoons, tornadoes and hurricanes are the different names of  tropical cyclones. Roaring forties is the name given to westerly winds originating in the subtropical region.

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Question E.4:

The clouds that occur at the highest level are

a. cumulus
b. stratus
c. cirrus
d. Nimbus

Answer:

The correct answer is option (c).

Explanation: Cirrus clouds are found at a height of around 6,000 metres from the sea level. They are very thin and have wispy strands.



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