Question

About 10% of solar energy is
A. Infrared
B. Ultraviolet
C. Visible
D. Harmful

Answer 1

Solar energy is the basic need for smooth functioning of ecosystems. Sunlight is composed of several radiations like infrared, ultraviolet, visible light, and gamma radiation in small amounts. Many harmful radiations are also present in sunlight.

Step by step answer: Sun is the primary source of energy for all living beings. Plants use solar energy for photosynthesis. Many radiations in sunlight are not reaching the earth’s surface as they are reflected by the earth’s atmosphere. Major components of sunlight are ultraviolet rays, infrared rays, and visible light. The visible light consists of 40% of total sunlight. It is the only component of sunlight that can be seen by our naked eye. There are several other radiations present that can’t be perceived by our eyes. They can be detected with the help of certain instruments. Infrared light is the major constituent which is about 50% of sunlight. Ultraviolet rays are present in about 10% and other radiations are also present in small amounts. The ultraviolet radiations are very harmful to us which is present in sunlight. Proteins and DNA of living organisms absorb the incoming UV rays and its high energy breaks the chemical bonds of these molecules. We are protected from the harmful UV rays with the help of an ozone layer which is present in the upper part of the stratosphere. It acts as a shield and absorbs the harmful UV radiation from the sun. UV-B radiation which is a type of UV radiation causes skin cancers, cataracts in the eye, aging of the skin, and snow blindness.
Hence, the correct answer is option B- Ultraviolet

Note: Ozone layer present in the stratosphere has been disrupted due to the increased emission of gases like chlorofluorocarbons. Once released into the atmosphere, they have permanent effects on the ozone layer. It leads to major health hazards to mankind.