Question

The percentage of solar radiation absorbed by all the green plants for the process of photosynthesis is about.
A. $1\% $
B. $5\% $
C. $8\% $
D. $10\% $

Answer 1

Hint: Much of the solar energy that we receive from sun is of the wavelengths that are unsuitable for photosynthesis. Almost 98 and 99 percent of solar energy that Earth receives is reflected from leaves and other surfaces and little amount is absorbed by other molecules, where it converts into heat energy. Therefore, only a small part is accessible to be captured by plants.

Complete answer: In the presence of the sunlight, chlorophyll and water plants make their food and release oxygen in the environment.
Solar radiation is radiant is a type of electromagnetic radiation or energy from the sun. It provides light and heat for the Earth and energy for photosynthesis. The three types of bands, or ranges in the solar radiation spectrum are ultraviolet, visible- Photosynthetically active radiation (PAR), and infrared. Solar radiation can be captured and turned into useful forms of energy like chemical energy provided by the process of photosynthesis in plants.
Photosynthetically active radiation is the range of visible light that plants can use for photosynthesis. It is the part of electromagnetic radiation that can be used as the source of energy for photosynthesis by green plants.
Percentage of photosynthetically active radiation (PAR) that is captured by plants in synthesis of organic matter is about 1-2 % of incident solar energy.
Hence, the correct option is, (a) $1\% $

Note:
-Higher plants make use of $1 - 2\% $ of sunlight for photosynthesis.
-Most crop plants reserve about $0.25\% $ - $0.5\% $ of the sunlight.
-The principal wavelengths of visible light that helps in photosynthesis occur within the blue range ( $425 -450$ nm) and red range ($600 - 700$nm). Therefore, the best light of the solar isolation for photosynthesis occurs in the blue and red ranges.