NCERT Class 11 Geography Chapter 31 Weather Instruments, Maps and Charts

NCERT Class 11 Geography Chapter 31 Weather Instruments, Maps and Charts Solutions to each chapter is provided in the list so that you can easily browse through different chapters NCERT Class 11 Geography and select need one. NCERT Class 11 Geography Question Answers Download PDF. NCERT Geography Class 11 Solutions.

NCERT Class 11 Geography Chapter 31 Weather Instruments, Maps and Charts

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. CBSE Class 11 Geography Solutions are part of All Subject Solutions. Here we have given NCERT Class 11 Geography Part I: Fundamentals of Physical Geography, Part II: Indian: Physical Environment, Part III: Practical Work in Geography. NCERT Class 11 Geography Notes, NCERT Class 11 Geography Textbook Solutions for All Chapters, You can practice these here.

Weather Instruments, Maps and Charts

Chapter: 31

GEOGRAPY [ PART – III ]

VERY SHORT ANSWER TYPE QUESTIONS

Q.1. What is the weather map?

Ans. A weather map is the representation of weather of a portion of the earth or a part of it on a flat surface.

Q.2. What do you mean by weather?

Ans. Weather refers to the atmospheric conditions prevailling at a specific time or over a short period.

Q.3. Name the instruments with which we find out wind directions.

Ans. Windvane.

Q.4. What is the use of Anemometer?

Ans. Anemometer is used for measuring the velocity of wind.

Q.5. With which instrument automatic recording of pressure can we done?

Ans. Aneroid Barometer.

SHORT ANSWER TYPE QUESTIONS

Q.1. What are the basic elements of weather?

Ans. The basic elements of weather are: Temperature, pressure, wind, humidity, cloudiness and precipitation. 

Q.2. Why and when the first weather maps were produced?

Ans. The necessity of having weather map was felt most by sailors. In 1688 Edmund Halley published a map for 30°N to 30°S in which showed the trade winds and direction on the monsoon winds.

Q.3. Name the organisation in India which records and monitors weather related data and information.

Ans. Indian Meteorological Department, Delhi records and monitors the weather related data and information.

Q.4. What are Isotherms?

Ans. Isotherms are lines connecting places of equal temperature.

Q.5. What are the three modes of meteorological observation used globally?

Ans. The three modes of observation are:

1. Surface observations: These observations are distributed all over the country and take observations according to globally coordinated time and spacing.

2. Upper air observation: There is a lage number of observatories located around the globe which release balloon-borne instruments for sensing different elements like temperature, humidity, wind and pressure in the upper atmosphere.

3. Space-based platform: In recent decades a powerful new tool has become available to the meteorologists in the form of artificial satellites to make comprehensive and large scale observation of different elements at the ground level and as also in upper layers of the atmosphere.

Q.6. What is a weather chart?

Ans. The data received from the various weather observatories are in plenty and detailed. They cannot be incorporated in one single chart unless coding designed to give economy of expression is used. These are called synoptic weather charts and the codes used are called meteorological symbols. Weather charts provide the primary tool for weather forecasting.

Q.7. What is the importance of weather forecasts?

Ans. Weather forecasts are very useful as they help us to take safety measures in advance in case of the likelihood of the bad weather, viz; storms, gales and heavy downpours. Farmers can save their crops from bad weather if they are told about it in advance. Weather forecasting is very essential for crewmen of ships and aeroplanes because bad weather hampers their work and often leads to serious accidents. Fishermen living in coastal areas depend much on weather forecasts because a sea storm can be dangerous to their lives.

Q.8. Which instruments are normally available in Class-I observatory to measure the weather phenomena? 

Ans. Weather Instruments: The following weather instruments are required to forecast the weather accurately:

1. Thermometer used for measuring temperature.

2. Maximum and Minimum Thermometer is used for recording the highest and lowest temperatures occuring during a given period.

3. Wet and Dry Bulb Thermometer used for recording the humidity in the air.

4. Barometer used for measuring atmosphere pressure.

5. Rain Gauge used for measuring the amount of rain.

6. Wind Vane used for knowing the direction of wind. It also tells us the speed of the wind.

7. Anemometer used for measuring the wind velocity.

LONG ANSWER TYPE QUESTIONS

Q.1. When was the Indian Meteorological Department established? Describe its role in the weather forecasting.

Ans. The need of starting a meteorological service in the country was first brought to the notice by the Asiatic Society of Bengal. The Indian Meteorological Department was started under the Government of India in 1688 with its headquarter at Pune. At present the headquarter is located in Delhi.

In India the meterological observatories are normally classified into five categories. Observations are taken in these observatories transmit the data to the central observatory at Pune twice a day for forecasting.

Q.2. Discuss how weather maps and charts are prepared and how are they useful to us.

Ans. The observations being taken at fixed hours are transmitted by code to the forecasting stations. The central office keeps a record of the observations which form the basis for making the weather maps and charts.

Weather maps and charts are useful to us. They provide the primary tools for weather forecasting. They help in locating and identifying different air masses, pressure systems etc. They are useful to pilots and defence personnels like farmers and fishermen.

Q.3. Describe the various weather symbols used in weather maps.

Ans. Weather elements are shown on the weather maps with the help of some symbols. These are internationally recognized and are called weather symbols. Different weather phenomena can be identified with the help of these symbols.

1. Pressure: Isobars are used to show atmospheric pressure of a place.

2. Temperature: Isotherms are used to show temperature of a place.

3. Winds: Wind velocity and direction is shown by arrows. The system was devised by Admiral Beaufort in 1806 and is known as Beaufort Scale.

4. Clouds: Circles used to show the nature and amount of cloudiness.

5. Rainfall: Certain symbols and letters are used to show rainfall and other atmospheric phenomena.

Q.4. Which meteorological symbols are used to mark the following on a weather map

(a) Rain.

(b) Mist.

(c) Sunshine.

(d) Lightning.

(e) Overcast sky.

Ans. 

Q.5. Name the instruments used for measuring the following:

(i) Continuous record of the atomospheric pressure.

Ans. Aneroid Barometer.

(ii) Direction of the wind.

Ans. Wind vane.

(iii) The velocity of wind.

Ans. Anemometer.

(iv) Humidity in the air.

Ans. Wet and Dry bulb thermometer.

(v) Maximum and minimum temperature for given period.

Ans. Maximum and Minimum thermometer.

(vi) The amount of rainfall.

Ans. Rain gauge.