The period of diffused light between sunset and complete darkness is called ……………. .

1. dawn
2. dusk
3. twilight
4. Both (b) and (c)

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.

Greenwich Mean Time : …………… :: Indian Standard Time : 12:00 pm

1. 6:30 am
2. 5:30 am
3. 6:30 pm
4. 5:30 pm

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