A teacher wants to discuss the theme of standard time in her class. Which of the following is/ are the most appropriate concept / concepts for this discussion (A) Latitude of the particular place (B) Longitude of the particular place (C) Local time (D) Comparative location of the place with respect to Greenwich. Choose the correct option.?

Option 2 : (B), (C) and (D)

The Indian Standard Time is calculated from 82°30'E meridian passing through Mirzapur.

• 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).
• India located east of Greenwich at 82°30'E is 5 hours and 30 minutes ahead of GMT.
• The latitude of a place may be determined with the help of the altitude of the sun or the Pole Star.
• The longitude of a place is its angular distance east or west of the Prime Meridian. It is also measured in degrees. The longitudes vary from 0° to 180°.

Prime Meridian- is also known as Greenwich Meridian.

• The Prime meridian is the most important line of longitude.
• It is located at zero degrees longitude (0˚).
• The Prime Meridian runs through Greenwich, a place near London.
• As the earth rotates from west to east, those places east of Greenwich will be ahead of Greenwich time and those to the west will be behind it.