UPSC Prelims Practice Questions — Department of Consumer Affairs Notifies Legal Metrology (Indian Standard Time) Rules, 2026
Q1. In the context of India's legal metrology framework, the 'One Nation, One Time' initiative refers to which one of the following?
- A. A proposal to merge India's two separately proposed time zones for the eastern and western regions into a single national time zone
- B. A directive requiring all States and Union Territories to align their office working hours and school timings to a common national schedule
- C. A project for nationwide dissemination of Indian Standard Time with millisecond-to-microsecond accuracy and its mandatory adoption as the sole legal time reference
- D. A move to shift India's civil clock from the 82°30′E meridian to a new reference meridian for uniformity with neighbouring countries
Q2. The high-power inter-ministerial committee constituted for the adoption of Indian Standard Time under the Legal Metrology Act, 2009 draws representation from several bodies. Consider the following pairs of body and its parent Ministry/Department:
1. CSIR-National Physical Laboratory — Ministry of Science and Technology
2. CERT-In — Ministry of Electronics and Information Technology
3. Securities and Exchange Board of India — Ministry of Consumer Affairs, Food and Public Distribution
4. Legal Metrology Division — Department of Consumer Affairs
Which of the above pairs is/are NOT correctly matched?
- CSIR-National Physical Laboratory — Ministry of Science and Technology
- CERT-In — Ministry of Electronics and Information Technology
- Securities and Exchange Board of India — Ministry of Consumer Affairs, Food and Public Distribution
- Legal Metrology Division — Department of Consumer Affairs
- A. 1 and 2
- B. 2 and 4
- C. 1, 2 and 4
- D. 3 only
Q3. Which one of the following statements about the authority under which Indian Standard Time is realised and maintained in India is correct?
- A. It is realised by the Bureau of Indian Standards, New Delhi, which is designated the National Metrology Institute of India
- B. It is realised at CSIR-National Physical Laboratory, New Delhi, which is mandated as India's National Metrology Institute by an Act of Parliament
- C. It is realised at CSIR-National Physical Laboratory, New Delhi, which functions under the Ministry of Consumer Affairs, Food and Public Distribution
- D. It is realised by the Indian Institute of Astrophysics, Bengaluru, which is the custodian of national measurement standards in India
Q4. Indian Standard Time, as adopted as the legal time reference for India, is best described as which one of the following?
- A. The local mean solar time of the 82°30′E meridian, which remains permanently and exactly identical to UTC+5:30 at every instant
- B. The arithmetic mean of the local solar times of all Indian States and Union Territories, recomputed afresh each year by CSIR-NPL
- C. Global Positioning System time advanced by 5 hours 30 minutes, generated entirely independently of any terrestrial atomic clock in India
- D. Coordinated Universal Time advanced by 5 hours 30 minutes, realised through a bank of atomic clocks and kept traceable to UTC
Q5. The draft Legal Metrology (Indian Standard Time) Rules were placed in the public domain for stakeholder comments by which one of the following?
- A. Department of Consumer Affairs, Ministry of Consumer Affairs, Food and Public Distribution
- B. Department for Promotion of Industry and Internal Trade, Ministry of Commerce and Industry
- C. Department of Scientific and Industrial Research, Ministry of Science and Technology
- D. Department of Telecommunications, Ministry of Communications
Q6. The draft Legal Metrology (Indian Standard Time) Rules were placed on the Department's website in January 2025 inviting stakeholder comments. The comment window allowed was of how many days?
- A. 15 days
- B. 30 days
- C. 45 days
- D. 60 days
Q7. Consider the following statements regarding the institutions and infrastructure involved in the Indian Standard Time dissemination project:
1. The National Primary Timescale from which IST is realised is maintained at CSIR-NPL and consists of a bank of caesium clocks together with active hydrogen masers.
2. ISRO, and not CSIR-NPL, is the body mandated by an Act of Parliament to function as India's National Metrology Institute and custodian of national measurement standards.
3. The project envisages dissemination of IST from five Legal Metrology laboratories located across India.
Which of the statements given above is/are correct?
- The National Primary Timescale from which IST is realised is maintained at CSIR-NPL and consists of a bank of caesium clocks together with active hydrogen masers.
- ISRO, and not CSIR-NPL, is the body mandated by an Act of Parliament to function as India's National Metrology Institute and custodian of national measurement standards.
- The project envisages dissemination of IST from five Legal Metrology laboratories located across India.
- A. 1 only
- B. 2 and 3 only
- C. 1 and 3 only
- D. 1, 2 and 3
Q8. Which one of the following correctly describes the institutional arrangement for the project to disseminate Indian Standard Time with millisecond-to-microsecond accuracy?
- A. Ministry of Electronics and Information Technology, in association with CSIR-NPL and the National Informatics Centre
- B. Department of Telecommunications, in association with C-DOT and the Bureau of Indian Standards
- C. Department of Scientific and Industrial Research, in association with CSIR-NPL and ISRO
- D. Department of Consumer Affairs, in association with CSIR-NPL and ISRO
Q9. Consider the following statements regarding the synchronisation requirements proposed under the Legal Metrology (Indian Standard Time) Rules, as compared with the position prevailing before them:
1. The Rules require systems to be synchronised with IST through the Network Time Protocol and the Precision Time Protocol.
2. Unlike the earlier position, the Rules make IST the mandatory time reference for commercial and financial entities as well, and not for government offices alone.
3. The Rules keep time-signal infrastructure outside any audit or penalty framework, leaving compliance with IST entirely voluntary.
Which of the statements given above is/are correct?
- The Rules require systems to be synchronised with IST through the Network Time Protocol and the Precision Time Protocol.
- Unlike the earlier position, the Rules make IST the mandatory time reference for commercial and financial entities as well, and not for government offices alone.
- The Rules keep time-signal infrastructure outside any audit or penalty framework, leaving compliance with IST entirely voluntary.
- A. 1 and 2 only
- B. 2 only
- C. 1 and 3 only
- D. 1, 2 and 3
Q10. Under the Legal Metrology (Indian Standard Time) Rules, deviation from IST is permitted, with prior government approval, for how many categories of specified purposes?
- A. Two
- B. Three
- C. Four
- D. Five
Q11. The expression 'legal metrology', as used in the Act under which the Indian Standard Time Rules are framed, refers to which one of the following?
- A. The branch of metrology concerned with establishing national primary standards and providing traceability of measurements to the SI units
- B. The branch of metrology concerned with calibration and control of measuring instruments used in manufacturing and industrial quality assurance
- C. The branch of metrology dealing with units, methods of weighment and measurement, and weighing and measuring instruments, in relation to mandatory technical and legal requirements
- D. The certification of products and services against published national standards, and the grant of conformity marks to consumer goods
Q12. The description of CSIR-National Physical Laboratory as the 'National Metrology Institute' of India denotes which one of the following roles?
- A. The statutory verification and stamping of weighing and measuring instruments before their use in trade and commerce
- B. Custodianship of the national standards of measurement, with responsibility for realising and disseminating the SI units in the country
- C. Formulation and publication of Indian Standards for products, processes and services across industrial sectors
- D. Grant of accreditation to testing and calibration laboratories operating in the country on the basis of international criteria