Characteristics of Light | Grade 7 Science DepEd MELC Quarter 3 Module 4

[Music] hi there have you ever wondered how a rainbow is formed a rainbow is a multicolored arc made by light striking water droplets it is the result of the refraction and reflection of light both refraction and reflection are phenomena that involve a change in a wave's direction scientists use the term electromagnetic spectrum to illustrate the entire range of light that exists from radio waves to gamma rays the human eye is only sensitive to a very narrow portion of the electromagnetic spectrum lying between the infrared and ultraviolet waves visible light is the only region of the electromagnetic spectrum the human eye can perceive when a narrow beam of white light enters a triangular block called a prism the beam splits into a different range of colors called spectrum the process by which light is separated into its colors due to differences in degrees of refraction is called this persian although white light can be split or dispersed into seven colors only three colors of light are required to combine and give white light these colors are red green and blue which are also known as the primary colors of light light is a form of energy that travels in electromagnetic waves it behaves like a wave thus it also has a wavelength amplitude wave speed and frequency visible light has wavelengths of 400 nanometer or nm for short to around 750 nanometer these wavelengths are represented by colors moreover each color corresponds to a specific range of frequency take a look at this illustration each color corresponds to a given wavelength and frequency redline has the highest wavelength and the lowest frequency from a wavelength of around 625 to 740 nanometer and a frequency of 405 to 480 terahertz or thc for short humans perceive the red color on the other hand violet light has the lowest wavelength and highest frequency as the wavelength decreases the frequency increases thus the color we perceive gradually changes from red to orange yellow to green then blue to violet colors like cyan and magenta are combinations of other wavelengths white represents the combination of all the wavelengths of the visible light while black is the absence of the wavelengths [Music] intensity or brightness is related to the waves amplitude the height of the amplitude tells the brightness of light thus the higher amplitude corresponds to a brighter light while lower amplitude corresponds to a dull light the measurement of the brightness of a light source is known as photometry there are three measurable quantities of light namely luminous intensity luminous flux and illuminance luminous intensity refers to the brightness of a light source and is measured in terms of candela luminous flux is the rate at which light is emitted from a source and strikes the surface of a whole sphere it is expressed in terms of lumens illuminance is the amount of luminous flux falling on a unit area of a surface measured in terms of lumens per square meter or lux now let's wrap things up visible light is the only region of the electromagnetic spectrum the human eye can perceive when a narrow beam of white light enters a prism the beam splits into a different range of colors called spectrum red light has the highest wavelength and lowest frequency while violet light has the lowest wavelength and highest frequency intensity or brightness of light is related to the waves amplitude photometry is the measurement of the brightness of a light source that's all for now we will be discussing about how heat is transferred and the conditions necessary for heat transfer to occur in our next video so stay tuned see you in our next video and don't forget to keep your minds busy if you like this video please subscribe to our channel and hit the notification icon for more videos like this

Channel: The Learning Bees

Views: 21,393

Keywords: The Learning Bees, Department of Education, DepEd, MELC-Based, Most Essential Learning Competencies, Science, MELC, Grade 7, Physics, Light, Characteristics of light, Optics, How rainbow is formed, Light prism, Electromagnetic Spectrum, Visible light spectrum, Dispersion of light, Amplitude, Wavelength, Wave speed, Frequency, Intensity of light, Photometry, Luminous intensity, candela, Luminous flux, lumens, Illuminance, lux, Ultraviolet, Infrared, X-rays, Gamma rays, Microwaves, Radio waves

Id: nuAA9OEINGc

Length: 5min 32sec (332 seconds)

Published: Wed Nov 03 2021