rays of sunlight moving straight from the sun perpendicular to the surface of the earth is called --------------------
The phenomenon you are referring to is called "direct sunlight." Direct sunlight occurs when rays of sunlight travel in a straight path from the Sun and strike the Earth's surface at a 90-degree angle (perpendicular). This typically happens when the Sun is higher in the sky, around midday or during summer months in certain regions.
To understand this concept, you can visualize the angle at which sunlight would hit different objects on the Earth's surface during different times of the day. You can also use basic geometry to determine the angle between the Sun and a specific location on the Earth's surface using the latitude and longitude of that location, along with the date and time.
If you want to determine the angle of sunlight at a particular location and time, you can use online tools or smartphone apps specifically designed for this purpose. These tools utilize algorithms and astronomical data to calculate the position of the Sun relative to a given location and time, allowing you to determine whether the sunlight is direct or at what angle it is hitting the surface.