NCERT Solutions for Class 11 Geography Chapter 30 - Weather Instruments, Maps and Charts

Question 1:

Which department prepares the weather map of India for each day?

  1. The World Meteorological Organisation
  2. The Indian Meteorological Department
  3. The Survey of India
  4. None of these
Answer:

(a). The Indian Meteorological Department.

Question 2:

Which two liquids are used in maximum and minimum thermometers?

  1. Mercury and water
  2. Water and alcohol
  3. Mercury and alcohol
  4. None of these
Answer:

(c). Mercury and alcohol

Question 3:

Lines connecting the places of equal pressure are called

  1. Isobars
  2. Isohyets
  3. Isotherms
  4. Isohels
Answer:

(a). Isobars

Question 4:

The primary tool for weather forecasting is:

  1. Thermometer
  2. Barometer
  3. Maps
  4. Weather charts
Answer:

(d). Weather charts

Question 5:

If there is more humidity in the air, the difference between the readings of a dry bulb and a wet bulb will be

  1. Less
  2. More
  3. Equal
  4. None of these
Answer:

(c). Less

Question 6:

Which meterological symbols are used to mark the following on a weather map?
(a) Rain
(b) Mist
(c) Sunshine (d) Lightning
(e) Overcast Sky

Answer:

Question 7:

What are the basic elements of weather?

Answer:

Temperature, pressure, humidity, rainfall.

Question 8:

What is a weather chart?

Answer:

Showing weather information.

Question 9:

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

Answer:

Maximum Minimum Temperature Sensor, Raingauge, Barometre, Wind Vane, Hygrothermograph.

Question 10:

What are Isotherms?

Answer:

This joining the places of was temperature reduced to sea level.

Question 11:

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

Answer:

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 from the basis for making the weather maps and charts. Weather maps and carts 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.