Question

How many meridians of longitude are there in the globe?

Answer 1

How many meridians of longitude are there in the globe?

A longitude line, or a meridian, is any line that runs from the north pole to the south pole.There are 360 degrees of longitude and the longitude line of 0 degrees is known as the Prime Meridian and it divides the world into the Eastern Hemisphere and the Western Hemisphere.

Meridians of longitude

• The lines of reference running from the North Pole to the South Pole are known as meridians of longitude.
• The value of this meridian is 0° longitude and from it we count 180° eastward as well as 180° westward.
• Longitude is given as an angular measurement ranging from 0° at the Prime Meridian to −180° westward to +180° eastward.
• The Prime Meridian and 180° meridian divides the earth into two equal halves which is known as the Eastern Hemisphere and the Western Hemisphere.
• Each degree of longitude is sub-divided into 60 minutes, each of which is divided into 60 seconds.
• The meridian which passes through Greenwich, where the British Royal Observatory is located is regarded as the Prime Meridian.
• A one-hour difference in local time corresponds to a difference of 15° longitude.

What is the use of the standard Meridian?

• To determine the local time of an area with respect to the time at the Prime Meridian (0°Longitude), we use the rate of the time at which the sun traverses over certain degrees of longitudes.
• The Standard Meridian is the time at the central meridian of the country and its local time is taken as the standard time for the whole country.
• This is done to maintain consistency of time within the political boundaries of a country to the maximum possible extent.
• Hence, the standard time for the whole country is the time along the Standard Meridian of India (82°30’E) which passes through Mirzapur. Mirzapur is located in Uttar Pradesh.
• There is a time lag of two hours, as we move from Gujarat to Arunachal Pradesh.