Answer:
Step-by-step explanation:
The Earth is a spherical shaped object
Hence ,
Due to the axial tilting of the sun rays , the rays does not reach Earth at an angle of 90 degrees . For example , at the equator the suns rays strike the earth vertically , hence more intense but as you move towards the poles the suns rays reach at different angles and hence intensity changes .
Conditions like fog and presence of clouds also affect the duration of radiation and its intensity .