Which one of the following statements relating to time is not correct ?
The local time difference between Gujarat and Arunachal Pradesh is around two hours
Gujarat saves about one hour time over the IST
Arunachal Pradesh loses about two hours time over the IST
The IST is advanced by five hours 30 minutes against the GMT
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CAPF – 2010
A) The longitudinal extent of India is approximately from 68.5°E (Gujarat) to 97.5°E (Arunachal Pradesh). The time difference between these longitudes is (97.5 – 68.5) * 4 minutes/degree = 29 * 4 = 116 minutes, which is close to two hours. Statement A is correct.
B) The Indian Standard Time (IST) is based on 82.5°E. Gujarat is to the west of IST. The time difference between Gujarat (approx 68.5°E) and IST (82.5°E) is (82.5 – 68.5) * 4 = 14 * 4 = 56 minutes. Gujarat’s local time is about 1 hour *behind* IST. The phrasing “saves about one hour time over the IST” is ambiguous but could be interpreted in terms of utilizing morning daylight, where sunrise happens earlier by local time than by IST clock. With this interpretation, it can be considered broadly correct in magnitude (~1 hour).
C) Arunachal Pradesh is to the east of IST. The time difference between Arunachal Pradesh (approx 97.5°E) and IST (82.5°E) is (97.5 – 82.5) * 4 = 15 * 4 = 60 minutes. Arunachal Pradesh’s local time is about 1 hour *ahead* of IST. Statement C claims it “loses about two hours time over the IST” and the magnitude is incorrect (it’s about 1 hour ahead, not 2 hours behind/losing). This statement is factually incorrect regarding both magnitude and relation to IST.
D) IST (82.5°E) is east of GMT (0°). The time difference is 82.5 * 4 minutes/degree = 330 minutes = 5 hours 30 minutes ahead of GMT. Statement D is correct.
Comparing B and C, statement C is clearly incorrect regarding the magnitude (2 hours) and the implied direction (loses time suggests behind, while it’s ahead of IST). Statement B’s phrasing is awkward but the magnitude is approximately correct (1 hour) and a possible interpretation makes it arguably correct. Therefore, C is the most definitively incorrect statement.