Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: The sun rises 2 hours later in Gujarat as compared to Arunachal Pradesh, but watches show the same time.
Reason R: The longitudinal gap between Arunachal Pradesh and Gujarat is about 30 degrees but at the same time India has adopted Indian Standard time which is at 82.5° West.
In the light of the above statements, choose the most appropriate answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A is correct but R is not correct
The Earth turns through 360° in 24 hours, that is 1° of longitude every 4 minutes, so sunrise comes later by 4 minutes for each degree one goes west.
Assertion A: The sun rises 2 hours later in Gujarat as compared to Arunachal Pradesh, but watches show the same time. Correct. India stretches from about 68°E (western Gujarat) to about 97°E (eastern Arunachal Pradesh), close to 30° of longitude, which is \(30\times4=120\) minutes, or about 2 hours. Yet clocks across India show the same time, because the whole country follows Indian Standard Time.
Reason R: The longitudinal gap between Arunachal Pradesh and Gujarat is about 30 degrees but at the same time India has adopted Indian Standard Time which is at 82.5° West. Not correct. The gap of about 30° is right, but Indian Standard Time is the local time of 82.5° East (passing near Mirzapur, Uttar Pradesh), not West; a West longitude lies in the Americas.