light beams of the sun 
We receive sunlight on earth surface. What type of light beams are these?
Random/Parallel/Converging/Diverging

I think it should be Diverging as Sun is radiating these beams away. But in one book, answer is given as Random, in another it's Parallel.
 A: "Beams of light" refer usually to an idea from geometrical optics, that light is composed of rectilinear beams. This is not entirely exact, as we know light is better described as a wave.
One can still use beams or rays if they are redefined as, say, lines of shortest path from the source of elementary (spherical) wave to the point of interest (eye...).
With such meaning, there are all possible beams (rays), going in all directions, so they may be called random.
Beams can be assumed as parallel if we discuss size of shadows in direct sunlight - they are almost the same size as the object casting them.
All beams are not exactly parallel, because the visible parts of the Sun radiate in all directions and their position on the sky is different. That's one reason why the shadows do not have absolutely sharp edge, but half-shade (penumbra) is present.
When thinking about Sun's radiation on large scales (Earth's orbit), or about light intensity decrease with distance, radial position becomes important. This leads people to think that the rays are radial (diverging) too. But only some of the rays are actually radial, for the same reason only some of them are parallel.
A: It is difficult to answer this question. An EM wave is generated by vibrating charges and nuclear reactions. Sun is full of vibrating charges and nuclear fusions. Because of this full range of frequencies are emitted. At distances close to sun we observe the directions of waves to be random. But at far away distances the direction of waves seem parallel. Since only parallel waves can have constant separation between them. Converging and diverging waves become distant at longer distances.
A: Jan L's answer is correct.  Consider as well: when there's a solar eclipse, there is a penumbra because, as he said, the sun is not a point source.
However, when dealing with a focussing system, the angle of divergence is close enough to zero that setting the lens to "infinity" is quite sufficient to focus an image of the sun.
