CBSE Class 6 Social Science Globe Latitudes And Longitudes Notes

Ql0. What is Prime Meridian?

The meridian that passes through Greenwich, where the British Royal Observatory is located is called the Prime Meridian.

Qll. What is the value of Prime Meridian?

Its value is 0° longitude and from it we count l80° eastward as well as l80° westward.

Ql2. How does Prime Meridian divides the Earth?

The Prime Meridian divides the earth into two equal halves, the Eastern Hemisphere and the Western Hemisphere. Therefore, the letter E for the east and W for the west follows the longitude of a place.

Ql3. How are latitudes and longitudes useful?

We can locate any point on the globe very easily if you know its latitude and longitude.

Ql4. Why is it necessary to have a standard time for a country?

The local time of places, are on different meridians, are bound to differ. It is, therefore, necessary to adopt the local time of some central meridian of a country as the standard time for the country. For ex. In India, the longitude of 821/° E (82° 301E) is treated as the standard meridian.

Ql5. What is IST?

In India, the longitude of 821/° E (82° 301E) is treated as the standard meridian. The local time at this meridian is taken as the standard time for the whole country. It is known as the Indian Standard Time (IST).

Ql6. What are the advantages and disadvantages of Globe?

Advantages- On the globe, countries, continents and oceans are shown in their correct size.

Disadvantages- Globes may be of varying size and type - big ones, which cannot be carried easily.

Ql7. What are the parallels of Latitudes? How are they measured?

All parallel circles from the equator up to the poles are called parallels of latitudes.

Latitudes are measured in degrees.

Ql8. What are " North Latitudes" and "South Latitudes "?

All parallels north of the equator are called 'north latitudes.' Similarly all parallels south of the equator are called 'south latitudes.' The value of each latitude is, therefore, followed by either the word north or south. Generally, the letter 'N' or 'S' indicates this.

Ql9. Name the important parallels of the Latitudes, along with their degrees?

There are four important parallels of latitudes-

(i) Tropic of Cancer (23.1/2° N) in the Northern Hemisphere.

(ii) Tropic of Capricorn (23.1/2° S) in the Southern Hemisphere.

(iii) Arctic Circle at 66.1/2° north of the equator.

(iv) Antarctic Circle at 66.1/2° south of the equator.

Q20. Explain the Torrid heat Zone?

The mid-day sun is exactly overhead at least once a year on all latitudes in between the Tropic of Cancer and the Tropic of Capricorn. This area, therefore, receives the maximum heat and is called the Torrid Zone.

Q2l. Explain the Temperate heat Zone?

The mid-day sun never shines overhead on any latitude beyond the Tropic of Cancer and the Tropic of Capricorn. The angle of the sun's rays goes on decreasing towards the poles. As such, the areas bounded by the Tropic of Cancer and the Arctic Circle in the Northern Hemisphere, and the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere, have moderate temperatures. These are, therefore, called Temperate Zones.

Q22. Explain the Frigid Zone?

Areas lying between the Arctic Circle and the North Pole in the Northern Hemisphere and the Antarctic Circle and the South Pole in the Southern Hemisphere are very cold. It is because here the sun does not rise much above the horizon. Therefore, its rays are always slanting. These are, therefore, called Frigid Zones.

Q23. What is the best means to measure time and how?

The best means of measuring time is by the movement of the earth, the moon and the planets. The sun regularly rises and sets every day, and is the best timekeeper throughout the world. The shadow cast by the sun can reckon local time, which is the shortest at noon and longest at sunrise and sunset.

Q24. Give some features of Latitudes?

• They are drawn between the poles.

• These circles run parallel to the Equator and never meet each other.

• 0° Latitude is Equator, which is the longest Latitude.

• They are 360 in number.

• Latitudes are not equal in size.

• The value of each latitude is followed by either the word north or south.

Q25. Give some features of Longitudes?

• They are drawn to join the poles.

• They are semi-circles and the distance between them decreases steadily pole wards until it becomes zero at the poles, where all the meridians meet.

• All meridians are of equal length.

• 0° meridian is called the Prime Meridian.

• They are l8l in number.

• The letter E for the east and W for the west follows the longitude of a place.

Q26. Why is it 5:30 P.M in India, When it is l2 noon at London?

India is located east of Greenwich at 82° 301E that is 5 hours and 30 minute ahead of GMT. So it will be 5:30 p.m. in India when its l2:00 noon in London.

Note - To calculate the time at any place following things are important-

> 1° = 4 minutes (Time taken by the sun light to cross one longitude)

> Time will increase (+) if we move towards East from Greenwich.

> Time will decrease (-) if we move towards West from Greenwich.

> To calculate the time, longitudinal value of the place is taken into consideration.