GLOBE: LATITUDES AND LONGITUDES Q1. What is a Globe? Globe is a true model (miniature form) of the earth. The globe is not fixed. It can be rotated the same way as topspin or a potter’s wheel is rotated. Q2. What is an Axis? A needle is fixed through the globe in a tilted manner, which is called its axis Q3. What are Poles? Two points on the globe through which the needle of the axis passes are called poles. Q4. What is the direction of the movement of the Earth? The earth moves from the west to east. Q5. What is an Equator? An imaginary line running on the globe divides it into two equal parts. This line is known as the equator. Q6. What is the degree of North and South Pole? 90 degrees north latitude marks the North Pole and 90 degrees south latitude marks the South Pole. Q7. Name the important heat zones of the Earth. Torrid heat Zone Temperate heat Zone Frigid Zone Q8. What are longitudes? The lines of reference running from the North Pole to the South Pole are called the Meridians of the longitude. Q9. How is the distance between the longitudes measured? The distances between the longitudes are measured in ‘degrees of longitude.’ Each degree is further divided into minutes, and minutes into seconds. Q10. What is Prime Meridian? The meridian that passes through Greenwich, where the British Royal Observatory is located is called the Prime Meridian. Q11. What is the value of Prime Meridian? Its value is 0° longitude and from it we count 180° eastward as well as 180° westward. Q12. 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. Q13. How are latitudes and longitudes useful? We can locate any point on the globe very easily if you know its latitude and longitude. Q14. 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 82½° E (82° 30'E) is treated as the standard meridian. Q15. What is IST? In India, the longitude of 82½° E (82° 30'E) 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). Q16. 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. Q17. 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. Q18. 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. Q19. Name the important parallels of the Latitudes, along with their degrees? There are four important parallels of latitudes– (i) Tropic of Cancer (23½° N) in the Northern Hemisphere. (ii) Tropic of Capricorn (23½° S) in the Southern Hemisphere. (iii) Arctic Circle at 66½° north of the equator. (iv) Antarctic Circle at 66½° 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. Q21. 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 Time keeper 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. What are parallels of Latitudes? They are the parallel circles running from the equator up to the poles. 0° Latitude is Equator, which is the longest Latitude. Latitudes are not equal in size. The value of each latitude is followed by either the word north or south. Q25. What are the Meridians of Longitudes? The lines of references running from the North Pole to the South Pole are called Meridians of Longitudes. 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. 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 12 noon at London? India is located east of Greenwich at 82° 30'E that is 5 hours and 30 minute ahead of GMT. So it will be 5:30 p.m. in India when its 12:00 noon in London. Note – To calculate the time at any place, following things are important1° = 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.