Samacheer Class 6 Social Science - Globe

When the sun is overhead on a particular line of longitude, it is 12 moon at all the places located on that line of longitude.
This is called local time.

There are imaginary lines which are drawn on the globe horizontally and vertically to find a location and calculate distance and time.
These imaginary lines are called lines of latitudes and longitudes.

From the Arctic circle (66 ‘A° N) to the North Pole (90° N) and from the Antarctic circle (66 Vi0 S) to the South Pole (90° S) the sun’s rays full further inclined, through out the year.
The temperature is very low.
Hence this region is known as Frigid Zone.

If the International Date line is drawn straight, two places in the same country would have different dates. So the International date line is found Zig Zag to avoid confusion.

Since the Earth is huge and we live on a very area, we are not able to see the Earth as a whole.
But when we travel to space, we can see the Earth as a whole.
So, in order to see the shape of the Earth as a whole and to know its unique features, a three-dimensional model of the Earth was created with a specific scale in the name of the globe.

Northern Hemisphere:
Northern Hemisphere. The area of the Earth found between the Equator (Oo) and the North pole (90oN) is called the Northern Hemisphere.

Southern Hemisphere:
Southern Hemisphere. The area of the Earth from the Equator (0°) and the South pole (90°S) is called the Southern Hemisphere.

Eastern Hemisphere:
Eastern Hemisphere. The part of the Earth between the 0° line of longitude and 180° East line of longitude is known as the Eastern Hemisphere.

Western Hemisphere
Western Hemisphere. The part of the Earth from Oo line of longitude and 180° West line of longitude is called as Western Hemisphere.

The significant lines of latitude are
Equator 0°
Tropic of cancer 23 1/2° N
Tropic of Capricorn 23 1/2° S
Arctic Circle 66 1/22°N
Antarctic Circle 66 1/2° S
North Pole 90° N
South Pole 90° S
Based on the amount of heat received from the sun, our world is broadly divided into three heat zones.
1. The Torrid Zone : On both sides of the equator, the region lying between the Tropic of cancer and Tropic of Capricorn is called the Torrid zone. This zone gets the direct rays of the sun all the year round. Hence the climate is hot and humid.
2. The Temperature Zone : This zone is neither hot nor very cold. It lies between the Torrid zone and Frigid zone in both the hemispheres.
3. The Frigid Zone : The region lying between the Arctic circle and North pole and between Antarctic circle and south pole is called the frigid zone. It receives very slanting rays of the sun and is therefore very cold.

The longitudinal extent of India is from 68° 7’E to 97° 25’E
Twenty nine lines of longitude pass through India.
Having 29 standard time is not logical
Hence 821/2° E line of longitude is observed as the prime meridian to calculate the Indian standard Time (IST)