GEOGRAPHY STD.9 LATITUDE & LONGITUDE 1. What is the Earth Grid? A. The complete network of meridians & parallels is called the earth Grid. 2. What is Latitude? A. The latitude of a place is the distance of that place north or south of the Equator measured as an angle whose apex is at the centre of the Earth. 3. Why are latitudes also called parallels? A. Latitudes are also called parallels because they are equidistant from one another. 4. Name the 5 important latitudes. A. The five important latitudes are:- The Equator 0 The Tropic of Cancer 23½ N The Tropic of Capricorn 23½ S The Arctic Circle 66½ N The Arctic Circle 66½ S 5. State the properties of the Lines of Latitude. They are angular distances north or south of the Equator. They are parallel to each other. They are circles that gradually get smaller until they are a point at the poles. The distance between 1 of latitude & another is 111km. There are 90 N/S latitudes. 6. Give reasons why the distance between the successive lines of latitude remains constant. A. The distance between two successive lines of latitude remain constant (111km) because latitudes are parallel to each other. 7. What determines the position of the 5 important latitudes? A. The latitudes are the angular distance of a place north or south of the equator. 1. The equator is the centre of the Earth 0 the area where the sun shines directly all year round. 2. The Tropic of Cancer 23½ N is the highest limit in the Northern hemisphere which receives the direct rays of the sun on 21 st of June. 1
3. The Tropic of Capricorn 23½ S is the highest limit in the Southern hemisphere which receives the direct rays of the sun on 22 nd December. 4. The Arctic Circle 66½ N is the place where the sun never sets on June 21 st & beyond this place we have six months of days & six months of night. 5. The Antarctic Circle 66½ S is the place where the sun never sets on Dec.22 nd & beyond this place we have six months of day and six months of night. 8. What are the characteristics of a) Torrid Zone b) Temperate Zone c) Frigid Zone Torrid Zone 0 23 1. Hottest zone 2. Sun is overhead twice in this zone 3. Widest of the 5 zones 4. The length of the day is practically the same throughout the year. 5. Very little difference between summer & winter Temperate Zone- 23½º - 66½ºN/S 1. Zone of moderate temperature 2. Great difference between summer & winter temperature. Range of temperature is great. 3. Sun is never overhead. Receives only slanting rays of sun. 4. Length of Day & Night very marked. 5. Most people live in this zone because of cool climate. Frigid Zone - 66½º - 90ºN/S 1. Coldest Zone because it is impossible for the slanting rays to reach beyond the 66½º N/S 2. It experiences 6 months of day and 6 months of night. 9. What are (a) mid-latitudes (b) low-latitudes (c) high-latitudes? a) Mid-latitudes are those latitudes between 30º- 60ºN/S b) Low-latitudes are those latitudes between 0º-30º N/S c) High latitudes are those latitudes between 60º-90º N/S 10. How do latitudes help us? A. Latitudes help us to know a) Climate of a place b) Vegetation c) Animal life d) Human life e) Along with longitude we can find out the location of a place 2
11. What is the total no. Of parallels of latitude that are drawn? A. They are 90º+90º+1º = 181º (Latitudes) 12. Which is the most important Latitude? Why? A. The most important latitude is the 0º or the equator. It is the most important parallel or latitude because it lies mid-way between the poles and is the base to measure all the latitudes north or south of the Equator. It also divides the earth into two equal hemispheres. 13. Which parallel is a Great Circle? A. The Equator 14. Which is the greater circle of latitude 10ºN or 60ºN? Give a reason for your answer. A. The 10ºN is a greater circle of latitude because latitudes are parallel to each other and as we go away from the Equator they get smaller until they are a point at 90ºN/S. 10ºN is closer to the equator than 60ºN. 15. What are longitudes? A. The longitude of a place is the distance of a place East or West of the Prime Meridian which is measured as an angle. 16. What is the reference meridian for measuring meridians of longitude? A. Prime meridian 17. What is the Meridian of Greenwich also called? A. The meridian of Greenwich is also called the Prime Meridian. It is 0º. 18. What is the 180º of longitude called? A. It is called the International Date Line. 19. Explain why the lines of longitude are called the meridians of longitude? A. The lines of longitude are called meridians of longitude because the word meridian means midday & all places along the same meridian experiences noon at the same time. 20. State the properties of longitude. A. The properties of longitude are- 1. They are semi-circles of equal length. 2. They converge at the poles. 3. The distance between two longitudes is not the same throughout. It is widest (111KM apart) at the equator and the distance decreases as we go towards the poles. 3
21. The distance between two consecutive parallels of latitude is equal to about 111KM, but the distance between two consecutive meridians of longitude is equal to 111km. Only at the equator. Why? A. The distance between two consecutive parallels of latitude is equal to 111km. Because they are parallel or equidistant throughout 40,000/360 while the distance between two consecutive meridians is 111km only at the equator because meridians are broadest at the equator & they converge at the poles, and hence they decrease. 22. How is longitude related to time? A. The earth rotates from west to east through the 360º in 24 hrs & so the sun appears to move from east to west at the rate of 15º in 1hr or 1º in 4 minutes. So places along the same longitude have the same time in both hemispheres. If a person travels eastward from Greenwich 15º his time is 1 hour ahead of Greenwich and if he moves westwards it is one hour behind Greenwich. 23. What is a Great Circle? A. A Great Circle is any circle that divides the sphere (Earth) into half & it is also the centre of the earth (SPHERE). 24. Why are all meridians of longitudes Great Circles? A. All meridians of longitudes are Great Circle because it divides the Earth into half and they are also the centre of the earth. 25. Why are parallels other than the equator not Great Circles? A. The Equator is the only parallel that is a Great Circle because it divides the Earth into two equal halves. All the other parallels or latitudes are smaller circles. 26. What is the advantage of following the Great Circle route in air travel? A. The Great Circle route is the shortest distance between any two points on the earth s surface. 27. Why do the sailors cannot take advantage of this Great Circle route always? A. Sailors cannot always take the Great Circle route because 1. It may take them into dangerous water. 2. It may take them through areas where ice is present & this is unsafe for navigation. 28. Explain how latitudes & longitudes enable us to find location of places on the earth? A. Latitudes are angular distance of a place north or south of the equator while longitude is an angular distance of a place east or west of the Prime Meridian. The complete network of meridians & parallels are called the Earth grid & this is what helps us determine the location of a place. 4
29. Give reasons:- a) The difference between GMT and Indian Standard Time (IST) is 5½ hours. A. The longitude of GMT is 0º The longitude of IST is 82½ºE For 1 hour = 15º 5 hours = 15 X5=75º 4 minutes = 1º 30 minutes = 30/4 = 7½ = 75+7½ = 82½ OR 1º - 4 minutes 82½º -? 165/2 X4 = 330/60 = 5½ hours b) The 0º meridian is known as the Prime meridian. A. The 0º meridian is known as the Prime Meridian because it is the reference line for measuring East West distance. c) The International Date Line is not a straight line coinciding with longitude 180º. A. The IDL is not a straight line so as to avoid land masses, allowing it to pass only over the water bodies to avoid confusion in Day & Date. If it were straight, then it would alter inhabited lands so that it might be 2 nd Jan Monday to one man and 3 rd Jan Tuesday to his next door neighbour. d) Canada has six Time Zones USA has 5 Time Zones & Soviet union has 11 Time Zones. Why do some countries have many time zones? A. This is because the longitudinal extent is very vast, hence they do not have a single Standard Time for the whole country. They have many time zones, with each time zone covering about 15º of longitude, The whole world is divided into 24 Time Zones. e) LOCAL Time differs from place to place. A. Local Time at a place is fixed with reference to the path of the sun in the sky. Local Time differs from place to place because of the variations in longitude. A longitude variation of 1º causes a time difference of 4 minutes. 30. What is Standard Time? A. Local Time varies from place to place & hence will cause confusion. Hence a uniform time throughout the country is adopted. It is based on the central meridian of the country or the meridian on which the most important city is located. The time on this meridian becomes the Standard Time for that country. 31. What is the local time difference between the Eastern most end and the Western most end of India? A. The difference is 2 hours. 5
32. How does Local Time differ from Standard Time? ( Write the definition of Local Time and Standard Time) A. 33. On which meridian is the Indian Standard Time (IST)? Name an important city through which it passes? A. 82½ºE Allahabad 34. Why the Standard Time is considered necessary? A. The local time varies from place to place. It will create considerable confusion if each place is to follow its own local time, and people travelling from one part of the country will have to adjust their watches according to the local time of that place. 35. What is the International Date Line? Mention two places where the International Date Line deviates from 180º longitude. A. The International Date Line is the 180ºE and west line. This longitude is diametrically opposite to that of the Greenwich Meridian. The International Date Line is not straight. It zigzags to avoid land masses. It passes only through water bodies. It marks the place on the earth s surface where each new date first begins. The International Date Line curves East of 180º in Bering Strait between Siberia & Alaska. It avoids the Hawaiian, Fiji, Tonga Islands. 36. Which parallel is a Great Circle? A. The Equator. 37. What is meant by Greenwich Mean Time? A. GMT is also known as Universal Time. It is the Time measured from Greenwich situated on 0º longitude & is used as a standard for reference all over the world. 38. What is meant by Indian Standard Time (IST)? A, IST is the time that is measured from Allahabad situated on 82½ºE longitude & is used as a standard for the entire country of India. 6
39. Distinguish between:- a) Equator and Prime Meridian Equator The equator is the reference line used for measuring distance to the north & south. Prime meridian The Greenwich or Prime Meridian is the reference line for measuring Esat- West distances. It converges on the two poles. b) Great Circle & Small Circle Great Circle 1. They divide the earth into two equal halves & are also the centre of the earth. 2. The radius of the Great Circle is the same as the radius of the earth. Small Circle 1. The centres of the small circles are points other than the centre of the earth. 2. The small circles have a radius which is smaller than that of the earth. 40. Name two countries which have more than one time zone. A. USA, USSR, Canada, Australia. 41. The lines of longitude are of equal length. What is the reason for it? A. All lines of longitude are of equal length because every longitude is a Great Circle & divides the earth into two equal halves & is also the centre of the earth. 42. Give reasons why a person travelling from Mumbai to London alters the time of his watch at several places? A. The person alters his watch many times because the East to West or longitudinal extent is very great. Hence he has to cross many longitudes & time zones. So for every longitude he crosses there is a time difference of 4 minutes, and for every time zone he crosses, the difference is one hour. Hence, as he is going to London, he crosses 5½ time zones. So the difference in time is 5½ hours & he is behind time. 7
43. Why does the sun rise at a different time at :- A (10ºN,15ºE) than at B(10ºN15ºW)? Also denote the position of any other place C at which the sun rises at the same time as at the place A. A. The sun rises at A first because A is 15ºE while B is 15ºW. So A is ahead of time by 2 hours than B. Place C (15ºN 15ºE) will have the same time as A. 44. What is the total no. Of meridians that are drawn? A. There are 360º (meridians of longitudes) 45. Distinguish between Latitudes and Longitudes. (The answer is the same as the definition of Latitude & Longitude). **************************************************************************. 8