Question

What is meant by advance sunrise and delayed sunset? Draw a labelled diagram to explain these phenomena.

Answer 1

The Sun appears about two minutes before the actual sunrise and this phenomenon is known as advance sunrise. The Sun remains visible about two minutes after the actual sunset and this phenomenon is known as delayed sunset. The advance sunrise and delayed sunset happen due to atmospheric refraction.
Sunrise means rising of the Sun above the horizon and sunset means setting of Sun below the horizon. The diagram given below shows the actual position (A) and the apparent position (B) of the Sun relative to the horizon.