Light energy is a type of kinetic energy because it deals with the speed of photons. Light energy is defined as a form of electromagnetic radiation emitted by the hot object like bulb, sun or fire e.t.c.
Emission of photons
When electrons in the atoms gain energy it goes to an excited state. Then electrons jump from valance band to the conduction band. Electrons jump back to the valance band by releasing of the photon after some time. That is visible to us. More photons come out as the substance gets hotter because is electron absorbs more energy and emits more numbers of photons.
Light travels in the form of a wave, no matter is essential to carry the light energy along to travel. This means that light energy does not require any medium for their propagation.
That’s why light can travel through space where there is no air. But the sound waves have to travel through solids, liquids or gas. Light energy travels faster than anything. The light speed is equal to 3×108 meters per second.
The sun releases a large amount of electromagnetic energy. Humans are only able to see a fraction of this energy which is known as visible light. The primary properties of visible light are propagation direction, intensity, frequency, wavelength spectrum, and polarization, and its speed in a vacuum. These all are described below;
The propagation direction of light
Light travel in a straight line. It does not change its direction until any hurdle is placed in front of it.
It may reflect or refract when it strikes on object
light reflection and refraction
• Reflection of light
When it strikes on the plane reflecting surface it reflects back into the same medium. In it the angle of the incident is equal to the angle of the refraction.
• Refraction of light
Refraction occurs when the light enters into the second medium and bends towards the normal.
Intensity of light
The intensity of light depends on the number of photons. If the number of photons is more than the light intensity is more. It the number of photons is decreasing than there is fewer numbers of photons.
Frequency of light
The one complete cycle is called the frequency. The frequency of light is directly proportional to it intensity and inversely proportional to the wavelength of the light.
The wavelength spectrum of light
The distance between two consecutive trusts or crust is called the wavelength. It is inversely proportional to the intensity of light.
Speed of light
The speed of light in vacuum is equal to 3×108 m/s.
Uses of Light Energy:
Light is the only form of energy that can be seen with naked eyes. There are also many scientific and commercial uses of light energy. Some of them are listed below.
Light is the only source of production of food for all living organisms. Every organism depends on light for their energy and food except a few bacteria.
Organisms are able to view the things in surrounding due to the presence of eyes. But eyes do not perform work without light. The eyes receive the image of an object when light falls on it and information is sent to the brain. Hence, light make possible for us to see objects around us.
Due to colors, the whole world is beautiful and all these colors are possible due to light. The light consists of many different spectra and every spectrum has an individual property of color which is broadly specified as VIBGYOR.
Light energy examples
- Daylight is the best model for light vitality. It is the regular wellspring of light vitality.
- The minute you hear light what’s that strikes is the daylight! Its that what makes you get up right off the bat in early daytime giving you a feeling of warmness and light. It warms the earth and makes the living creatures to continue. It adjusts the biological system and the world would have smashed without it!
- Light vitality can be changed over into compound vitality when the plants assimilate the light vitality, they convert it into concoction vitality for their own sustenance.
- Another genuine model is the sun, the sun gives plants light vitality which a short time later is changed over into concoction vitality.
- Light vitality can likewise be changed over into warm vitality when for instance the sun warms up your dark shirt or a block divider outside.
- There are numerous model we find in our standard life conveying light vitality like helped flame, streak light, fire, Electric bulb, lamp oil light, stars and different glowing bodies and so forth. Each go about as a wellspring of light.
- Indeed, even a consuming flame is a model for light vitality.