Latitude Longitude and Time

CBSE Class 11 Geography

NCERT Solutions
Chapter 26
Latitude, Longitude and Time

1. Answer the following questions in about 30 words.
(i) Which are the two natural points of references on the earth?
Ans. North Pole and South Pole are the two natural points of references on the earth.

(ii) What is a great circle?
Ans. A great circle is the largest possible circle that can be drawn round a sphere. Equator is also called a great circle.
The line drawn midway between the North Pole and the South Pole is called the equator. It is the largest circle and divides the globe into two equal halves.

(iii) What are coordinates?
Ans. A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols.The coordinates are often chosen such that one of the numbers represents a vertical position, and two or three of the numbers represent a horizontal position. The latitudes and longitudes are commonly referred to as geographical coordinates as they provide systematic network of lines upon which the position of various surface features of the earth, can be represented.

(iv) Why does the sun appear to be moving from east to west?
Ans. The earth actually rotates from west to east because of its own rotation on its axis and therefore, the sun appears to be moving from east to west, because it is stationary and an observer on the surface of the Earth would see the Sun moving from east to west.

(v) What is meant by local time?
Ans.Local time is the time at a particular place as measured from the sun's transit over the meridian at that place. The rate of the time at which the sun traverses over certain degrees of longitudes is used to determine the local time of an area with respect to the time at the Prime Meridian.(0°Longitude).

2. Distinguish between latitudes and longitudes:
Ans. The difference between latitudes and longitudes is as follows:

Basis	Longitude	Latitude
Meaning	The meridians of longitude refer to the angular distance, in degrees, minutes, and seconds, of a point east or west of the Prime (Greenwich) Meridian.	The parallels of latitude refer to the angular distance, in degrees, minutes and seconds of a point north or south of the Equator.
Name	Lines of longitude are often referred to as meridians.	Lines of latitude are often referred to as parallels.
Reference point	0° longitude is called prime meridian.	0° latitude is called equator.
Division	It divides the earth into eastern hemisphere and western hemisphere.	It divides the earth into northern hemisphere and southern hemisphere.
Number	These are 360 in number: 180 in the eastern hemisphere and 180 in the western hemisphere.	These are 180 in number excluding the Equator: 90 in southern hemisphere and 90 in northern hemisphere.
Importance	It helps to determine time of a place.	It helps to determine temperature of a place.
Equality	These are not equal.	These are equal.

Latitude Longitude and Time - Solutions