The Indian Standard Meridian passes through 5 States. Which of these states is NOT among the five?

Answer: (3) Bihar

Explanation:

The Indian Standard Meridian (82.5°E longitude) is the basis of Indian Standard Time (IST), which is UTC+5:30. 

• It passes through five Indian states: Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Odisha, and Andhra Pradesh. 
• India follows only one official time zone, despite its wide east-west geographical extent. 
• The standard time is calculated using the mean solar time at 82.5°E longitude, which passes through Mirzapur in Uttar Pradesh. This uniform time system supports national coordination in governance, transport, communication, and business across the country.

A proposal by CSIR-National Physical Laboratory (CSIR-NPL) suggests introducing two time zones. IST-I would cover most of India, while IST-II would cover the northeastern states with a one-hour difference. The proposal aims to improve daylight utilisation, increase energy efficiency, and enhance productivity, although concerns remain regarding coordination, infrastructure, and administrative complexity.