ICSE CLASS 9 GEOGRAPHY LATITUDES AND LONGITUDES

Q.1. What do you mean by geographical grid?

Ans. The geographical grid is the network of latitudes and longitudes used for locating any place accurately over a map or globe.

Q.2. What do you mean by latitude?

Ans. Latitude is the angular distance of a point, north or south of the equator from the center of the Earth. It is usually measured in degree, minute and seconds.

Q.3 Why latitudes are also called as parallels of Latitude? Ans. The lines of latitude run parallel to equator as well as to each other. So they are called parallels or latitude.

Q.4. Which pressure belt is known as 'horse latitude"? Why?" 

Ans. Subtropical high pressure belt that lies between 25° to 35 N and S is called as horse latitude. it known as horse latitude because during ancient days sailors used to unload their horses (cargo) in the sea to make their ships lighter.

Q.5. Name the latitudes which demarcate the northern and southern limit of the torrid zone." 

Ans. The boundary of Torrid Zone has been demarcated by Tropic of Cancer (23.5° N) in the north and Tropic of Capricorn (23.5° S) in the south.

Q.6. What do you mean by longitude?

Ans. Longitude is the angular distance between the Prime meridian at Greenwich and a point on any meridian on the surface of earth. It is expressed in degrees, minutes and seconds. 

Q.7. Write the name of the most important latitude and longitude?

Ans. The most important latitude is equator and the most important longitude is Prime Meridian. 

Q.8. What is equator and how is it important to us?

 Ans. Equator is the imaginary line that runs through the center of the Earth horizontally and divides the Earth into two equal halves Le. Northern Hemisphere and Southern Hemisphere.

 Q.9  What is Prime Meridian and how is it important to us? 

Ans. Prime Meridian is an imaginary line that passes through the city of Greenwich, England. Like the equator it also divides earth into two equal halves but vertically, Le. Eastern and Western Hemispheres. It is also considered as the base for determining time zones of the world. It is known as Greenwich meridian.

Q.10. Why are longitudes also called meridians?

Ans. Meridian means midday. When the Sun is overhead on a certain longitude it is midday or noon for that particular longitude. Thus longitude is also known as meridians.

Q.11 Which longitude is used for determining the world standard time and what is the value of it?

Ans. The value of longitude passing through Greenwich city in London is used for determining the world standard time. The value of Greenwich mean time is 0° longitude.. 

Q.12  Calculate the time of a place located at 30" E Longitude, when it is 10 P.M. at 30° W longitude."

Ans. The time at 30° W 10:00 P.M.

Time difference at 30° E-60-4 is 240 minutes or 4 hours Because 30° E lies in the Eastern Hemisphere, we will add the time

Thus, the time at 30° E is-10:00 +4 hours -2:00 A.M.

Q.13. What do you mean by a globe?

Ans. Globe is the spherical representation of the earth with a network of latitude and longitude drawn over it. The globe serves the purpose of identifying various features of the earth surface. 

Q.14. State the importance of pole star.

Ans. Pole star is the only star which is located directly above the North Pole and this is the reason it hardly appears to move or changes its position. It helps in getting the north direction as its position remains unchanged all through the night and year. 

Q.15  What do you mean by local time?

Ans. Local time means the time of a certain place determined on the basis of the apparent movement of the Sun. When the Sun is at its highest point or zenith, the time happens to be noon there. It varies by minutes for every longitude.

Q.16. What do you incan by the Standard Time?

Ans. The Standard Time is the official time of a country based on the standard ineridian passing through it.

Q.17 What do you mean by Indian Standard Time?

Ans Indian Standard Time is the time observed through out India Le GMI 05:30 hours. The times determined on the basis of the Standard Meridian of India which passes through 85.5°E (82°30'E)

Q.18. What do you mean by a time zone and why it is required?

Ans. A time zone refers to a region of the globe that follows a uniform standard time so as to satisfy social legal and commercial purposes. Time zones are required when countries have vast east-west longitudinal extent. Practically it is impossible to have one standard time when the east west extent a country is too large. Thus we require more than one time zone instead of only one for such countries

Q.18 What do you mean by the International Date Line? 

Ans. The International Date Line refers to the north-south imaginary line on the surface of earth that passes through the Pacific Ocean. It is accepted internationally that a new calendar day begins at this line One day is on the east of this line and the following day is on the west of this line.

Q.19. What do you mean by great circle route and how they are important?

Ans. A great circle refers to any circle on the Earth's circumference whose centre coincides with the centre of the Earth Since a great circle represents the shortest distance between two point anywhere on the Earth's surface, they are mostly followed by sailors and pilots for navigation.

 Q.20.Name a latitude which forms a Great Circle."

Ans. Equator or 0° latitude forms Great circle.

Q.21.. What do you understand by the Standard Meridian?

Ans. A meridian or longitude is selected as a standard time for a country on which the most important city is located or part of it is called as Standard Meridian.

 Q.22 Why it is practical to follow standard time rather than the local time?"

Ans. It is practical to follow standard time rather than the local time because following the local times i a country will create confusion for its citizens. Moreover, people travelling from one time zone to another will always direct their watch according to their location. 

Q.23 What is a time zone? How many time zones are there in the world?"

 Ans. A time zone is a region on a globe that experiences similar standard time. There are total 24 time zones.