The duration of twilight :

1. increases to the poles
2. might last for as much as 7 weeks at the poles
3. is as long as the sun is 18° below the horizon
4. all of the above.

World Standard Time: 0° :: Indian Standard Time : ……………

1. 23½°
2. 72½°
3. 66½°
4. 82½°

Assertion (A): Phenomena of dawn and dusk is experienced more in temperate regions.

Reason (R): The twilight continues as long as sun is 18° below the horizon.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R does not explain A.
3. A is true but R is false.
4. A is false but R is true.

World Standard Time : …………… :: Indian Standard Time : Standard Meridian of India

1. World Standard Meridian
2. Prime Meridian
3. International Date Line
4. Greenwich Mean Time