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Question Gamma raysX-raysInfra-red raysUV raysHint: These rays can promote local blood circulation and reduce muscle tension. These rays lie between visible and microwave rays.The correct answer is: Infra-red raysElectromagnetic waves in order from shortest to longest wavelength- gamma rays, x-rays, ultraviolet rays, visible rays, infrared rays, microwaves, and radio waves.Therefore, infra-red rays has longer wavelength than visible light.So, the correct option is c.Related Questions to study
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Chapter 2
In order to truly understand the tanning process of the skin you need to have at least a basic understanding of the properties and function of light. Although light has played a central role in the histories of religion, art and science and is so common to our everyday existence, it can actually be quite elusive. Understanding Ultraviolet Radiation Electromagnetic Spectrum UVA is found in the region between 320 and 400 nm and is the least powerful wavelength band of UV radiation. UVA acts primarily to cause the melanin pigments in the skin to oxidize (darken) creating the cosmetic tan and has limited power to cause erythema. UVB is found in the region between 280 and 320 nm. It comprises the wavelengths primarily associated with erythema (sunburn), is also necessary for the production of vitamin D in the skin and is primarily responsible for stimulating increased melanin production. UVB wavelengths (at 305 nm) have 1,000 times more erythemal power than UVA wavelengths. UVC is found in the region between approximately 200-280 nm and is called germicidal UV because of its proven effectiveness in killing sing-cell organisms. Solar radiation in the UVC range is absorbed almost entirely by the atmosphere and that is fortunate considering that even a short overexposure to UVC is very harmful to the eyes and causes severe erythema (sunburn). One place where radiation in the UVC range can be found is in the arc of a welding torch. For that reason, optical damage referred to as "welders eye" is caused by UVC light. It should be noted that UVC wavelengths are not produced by the UVR sources utilized by the indoor tanning industry. Wave Theory Electromagnetic waves all travel at the same constant speed as light, 186,000 miles per second in a vacuum. All electromagnetic waves have the same form and travel at the same speed, but differ in wavelength. Wavelength is the distance between two successive crests in the wave. The number of crests or cycles per second is the frequency of the wave. The unit of frequency is hertz or 1 cycle per second. Therefore, if the wavelength is decreased, then the frequency is increased. Frequency and wavelength have an inverse relationship which is calculated with one of two equations: (see illustration) Electromagnetic Spectrum Frequency = velocity of radiation / wavelengthor Wavelength = velocity of radiation / frequency Where the velocity of radiation is 186,000 miles per second. Frequency is calculated using cycles per second and wavelength is calculated in meters. The wavelengths of electromagnetic radiation vary in size from a fraction of an angstrom unit (an angstrom is equal to ten billionths of a meter) to thousands of meters, commonly called the "electromagnetic spectrum." Some of the wavelengths of electromagnetic radiation from this spectrum are classified as follows:
Therefore, the useful unit of measure for our purposes is the nanometer. Radiations shorter than 10 nanometers (i.e. gamma rays or X-rays) generally ionize molecules (remove electrons) producing positively or negatively charged ions and are, therefore, known as ionizing radiation. Ultraviolet radiation is absorbed by molecules and is known as nonionizing radiation. Quantum (Particle) Theory Light energy is expressed differently. We often express radiant energy in terms of watts per square meter or milliwatts per square centimeter. Skin exposure is usually expressed in joules per square centimeter. A Joule, is a unit of measurement and is equivalent to the electrical work done in one second by an electrical current of one ampere through the resistance of one ohm; named for its inventor, British Physicist, J.P. Joule (1818-1889). What has a longer wavelength than visible light?Infrared radiation, what we experience as heat when we hold our hand near a warm object, is somewhat longer wavelengths than visible light.
Does ultraviolet light have a higher frequency than visible light?Electromagnetic waves with wavelengths just shorter than those of visible light are called ultraviolet rays. Ultraviolet rays have higher frequencies than visible light, so they carry more energy.
Does infrared light has a longer wavelength than visible light?Infrared waves have longer wavelengths than visible light and can pass through dense regions of gas and dust in space with less scattering and absorption. Thus, infrared energy can also reveal objects in the universe that cannot be seen in visible light using optical telescopes.
Does ultraviolet light have shorter wavelengths and higher frequencies than visible light?UV has a higher frequency and shorter wavelength than visible light, and it has a lower frequency and longer wavelength than X-radiation.
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