Question

discuss the factor affecting solar radiation

Answer 1

Hello....
The amount of solar radiationreaching the earth's surface varies greatly because of changing atmospheric conditions and the changing position of the sun, both during the day and throughout the year. ... For any given location, the solar radiationreaching the earth's surface decreases with increasing cloud cover.

Answer 2

The amount of insulation received at particular place and time depends on the following factors:
1. Distance from the sun. 
2. Duration of daily sunlight period.
3. Solar elevation or inclinations of the solar rays to the horizon.
4. Transparency of the atmosphere towards heat radiation and 
5. Output of solar radiation.

The first three of these reasons are intimately connected with revolution of earth, It is to be noted here that the earth revolves about the sun in elliptic orbit and makes one complete revolution in 365 days, simultaneously it spins about itself and complete one rotation in 24 hrs.

The average distance of the earth from the sun is 149.5 million km).
The duration f daylight also varies with the latitude and season.  Longer the day light duration, greater is the insulation received, In the solar region the duration of day light is 24 hrs during summer and minimum of zero in winter season.