Electromagnetic Radiation Essay
explanatory Essay
916 words
Introduction:
Scientists and engineers have been able to enhance our lifestyles by understanding and using the Laws, Concepts and Principles of Optics and how they are applied in Optical Instruments. The key concepts are:
a. Lights as a form of electromagnetic radiation
Electromagnetic radiation is a term used to describe a pair of electric and magnetic fields that promulgate together at the speed of light. This means that light holds electric and magnetic components. The accelerated movement of electric charges emits radiation. This radiation is visible to us as light.
Figure 1: electromagnetic waves
Time-varying electric fields can bring magnetic fields and vice-versa. Since both fields generate each other, they occur jointly and therefore, propagate as electromagnetic waves.
The electromagnetic radiation of light is a small part of the electromagnetic spectrum.
Like all wave phenomena, radiation is considered by its wavelength and its frequency f. Electromagnetic radiation promulgates at the speed of light c. The equation is: .
Application such as the sun emits most of its radiation in the visible range which our eyes recognize as the color of rainbow.
b. Law of reflection
The law of reflection states that when a ray of light strikes a plane mirror, the light ray is reflected off the mirror as such that the angle of reflection is equal to incidence angle. The diagram below illustrates the law.
Figure 2: angle of reflection=angle of incidence
In the diagram, the light approaching the mirror is the incident ray and the light leaving the mirror is the reflected ray. The line perpendicular to the mirror is the normal line. The angle between the incident ray and the normal line is the angle of incident and the angle of r...
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Rainbow color components are evident through dispersion of visible light and total internal reflection in prisms.
6. Refraction in lenses
The refractive index of lens is larger than air therefore refraction in lenses occurs differently. It happens when light moves parallel to the normal and is refracted through the focal point. If a ray passes through the optical center of the lens, the ray would continue without being refracted. The optical direction is the point on the normal where the incident direction of a ray is parallel to the emergent direction.
Figure 13: converging lens
In a convex lens, the rays are parallel to the axis (normal) and cross each other at a single point on the focal point. This is called converging lens.
Figure 14: diverging lens
In a concave lens, the light rays bend away from the normal. This is known as diverging lens.
In this essay, the author
- Describes how scientists and engineers have been able to enhance our lifestyles by understanding and using the laws, concepts and principles of optics and how they are applied in optical instruments.
- Describes electromagnetic radiation as a pair of electric and magnetic fields that promulgate together at the speed of light.
- Explains that time-varying electric fields can bring magnetic fields and vice-versa. since both fields generate each other, they occur jointly and propagate as electromagnetic waves.
- Explains the law of reflection, which states that when light strikes a plane mirror, the light ray is reflected off the mirror.
- Explains that in the diagram, the incident ray and the light leaving the mirror are the reflected radii. the normal line is the angle of incident and reflection.
- Explains that electromagnetic waves reflect light in a variety of directions, called diffuse reflection, and specular reflection.
- Explains that if a ray of light moves parallel to the axis of the mirror and then strikes it, it will be reflected through the focus.
- Explains that if a ray of light travels through the focus of the mirror and then strikes it, it will be reflected parallel to the axis.
- Explains that if a ray of light passes through the center of the mirror's curvature, it will be reflected back through its center.
- Illustrates that the focus, ‘f’, is half-way between the mirror and the curvature, where light rays travel parallel to the principal axis after reflection.
- Explains that the equation represents the relationship between 'do', which is the object distance, and the image distance.
- Explains snell's law of refraction, a formula used to define the relationship between the angle of incidence and the bending of light as it moves across two separate media.
- Illustrates how light bends when it enters medium 2. water is denser than air, which means water slows down light. the frequency remains the same, but the wavelength reduces.
- Explains that visible light is also called white light, which consists of constituent colors. the term visible spectrum can be observed when light passes through a triangular prism to separate into its colors, known as dispersion.
- Explains total internal reflection (tir) occurs when light passes from a given index of refraction to the medium of low index. the critical angle of incidence, c, is the refracted rays.
- Explains that light passes through optical fibers, which are very thin core of high purity glass, covered by a second layer called the cladding and is less dense than the core.
- Explains that rainbow color components are evident through dispersion of visible light and total internal reflection in prisms.
- Explains that the refractive index of a lens is larger than air therefore refraction in lenses occurs differently.
- Describes a convex lens where rays are parallel to the axis and cross each other at one point on the focal point.
- Explains that in a concave lens, the light rays bend away from the normal. this is known as diverging lens.
- Explains that radiation is considered by its wavelength and frequency. electromagnetic radiation promulgates at the speed of light.
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- explanatory
- Electromagnetic Radiation Essayexplanatory essayIntroduction: Key Concepts: Light as a form of electromagnetic radiation: Light can be classified as a form of electromagnetic radiation, which includes visible light. The ‘light’ commonly referred to in everyday life belongs in this category. The electromagnetic spectrum includes other types of radiation such as gamma rays, radio waves and cosmic rays, all of which possess distinct wavelengths, frequencies and energy levels. These forms of electromagnetic radiation are not visible to the human eye but can be perceived by selected species of animals, such as bees. Figure 1 below displays the electromagnetic spectrum and provides a basic insight into the respective characteristics of different forms of radiation.
In this essay, the author
- Explains that light can be classified as a form of electromagnetic radiation, which includes visible light. the electromagnetic spectrum includes gamma rays, radio waves and cosmic
- Explains that light is a series of self-propagating transverse waves composed of electric and magnetic fields. the distance between successive waves is known as the wavelength, denoted by the symbol.
- Illustrates the angle of incidence of an incident ray hitting a plane surface. the law of reflection states that i=r.
- Explains that reflection in curved mirrors refers to reflections in two types of mirror: concave and convex.
- Explains that curved mirrors can be considered as a section of an imaginary sphere. the principal axis is the line passes through the centre of curvature with one end touching the exact centre.
- Explains that light follows the law of reflection in all mirrors, however in curved mirror, the normal is the line that extends through the centre of curvature (c) from the point of incidence.
- Explains that when an object is placed in front of a curved mirror, its image is reflected within the mirror. there are several ways to determine the location and properties of this image.
- Illustrates how concave mirrors can produce both real and virtual images depending on the position of the object.
- Explains that there is a formula for determining either the object distance, image distance or the focal length if two of the other variables are known.
- Explains that convex mirrors reflect light parallel to the principal axis, and rays of light travelling parallel will be reflected along the line extending towards the virtual focus, located on the other side.
- Explains that light travels in straight line paths in all media at different velocities depending on the medium. the law of refraction governs the angle at which the light ray is refracted.
- Explains that the refractive index of a vacuum is 1, as c and v are equal.
- Explains that light coming from a given point on the straw submerged in water will refract as it crosses over to the air, away from the normal.
- Explains that light is a form of electromagnetic radiation or wave, consisting of waves which vibrate at different frequencies. the visible spectrum is situated between ultraviolet and infrared on the electromagnetic spectrum.
- Explains that white light can be separated so that its individual wavelengths and therefore colours are apparent to the human eye.
- Explains that not all rays of light passing through glass prisms are refracted and divided into their colours.
- Explains that refraction in lenses concerns two main types: concave and convex. lenses are typically constructed out of glass or perspex and have been used in a variety of optical instruments.
- Explains the properties of a convex or converging lens based on the object's position from the lens.
- Explains that concave lenses produce virtual images that are diminished and upright, regardless of the object's position. the virtual image can be found by tracing incident rays back to the point from which they appear to have come from.
- Explains that slide projectors project an image imprinted on a slide using optical devices such as mirrors and lenses. the light source is placed at the centre of curvature of the concave mirror and passes through convex lenses, which act as condensers.
- Explains that after passing through a slide, the rays travel through the projection lens located beyond it, resulting in the magnification of the image on the screen. the distance between the slide and the lenses can also be adjusted.
- Explains lcd (liquid crystal display) projectors utilize dichroic mirrors or prisms that separate light from the light source into ldc panels of the colours red, green and blue.
- Explains that lcd projectors also rely on optical instruments such as prisms, mirrors and lenses, similar to the requirements of a slideshow.
- Explains how the keplerian telescope uses convex lenses to magnify an image. however, chromatic aberration occurs due to failure to converge all wavelengths of the visible spectrum at one point.
- Explains the law of reflection, which predicts the angle at which light is reflected off of a plane surface.
- Explains that the refractive index determines whether the light refracts at a lesser or greater angle. the relationship between the angle of incidence and the ray of light is summed up in the snell’s law.
- Explains total internal reflection (tir) occurs when the light ray exits the denser medium and enters a comparatively less dense medium.
- Explains that metamaterials are composed of a repeating series of elements with dimensions smaller than that of the wavelengths of light it intends to manipulate.
- Explains that optical instruments are used to manipulate the audience's perception of the stage and its occupants as well as direct their attention to particular sections.
- Explains that holograms are 3d images encoded onto a 2d surface, which acts as recording medium. they make use of optical devices such as mirrors, prisms and lenses.
- Explains that reflecting telescopes employ mirrors and lenses to avoid chromatic aberration. the newtonian telescope uses a concave mirror to allow the incoming parallel light rays to bounce off, before continuing along its path and passing through the convex lens.
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In this essay, the author
- Describes the objectives of the laboratory experiment to design and explain the newton's telescope.
- Explains the angular magnification of a newton's reflective telescope, which is defined as the ratio of the image seen looking through the telescope to the object viewed with the unaided eye.
- Explains that for objects outside the focal point, an inverted real image is formed, and an erect virtual image will be the outcome. the refracted rays are traveling parallel to each other.
- Explains that the magnification equation consists of 1/0+1/f = 1 / i. the virtual image formed by the convex lens is negative, whereas f is positive for the diverging mirrors.
- Explains that the ray diagrams for the concave lenses inside and outside the focal point produce erect virtual images that are smaller than the objects.
- Explains that the equation behind the image formation is illustrated as 1/0+1/f = /f. the i is positive for a real image, whereas the 0 is normally negative.
- Illustrates the formation of the image amid using two mirrors within the newton's telescope.
- Explains newton's refractive telescope, which uses mirrors, rather than lenses, to bring the light to a focus.
- Illustrates the principles behind the ray tracing techniques in the newton's telescope.
- Concludes that newton's work set the stage for future developments of the telescope. reflecting light rather than refracting it solved the problem.
- Cites atwood, jenny, ely, cassar, and escarrat's contributions to the spie astronomical telescopes+ instrumentation.
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699 wordsRead More - How is Bluetooth is a Modern Application of Physicsexplanatory essayNature of wave: It is an electromagnetic wave as it does not necessarily require a medium for p...
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- Explains how a small bluetooth chip replaces cables and transmits information to the receiver via an antenna. the wave is produced by the movement of electrons in the antenna when data is transmitted from the master device.
- Explains that the wave is detected when the data transmitted is successfully received by the slave device.
- Explains that a wave is an electromagnetic wave as it doesn't require any medium for propagation, but in the case of bluetooth air is the medium. a transverse wave moves its particles at right angle to the direction of the wave.
- Explains that the wavelength of the microwave transmitted by bluetooth is about 12.5cm.
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In this essay, the author
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In this essay, the author
- Explains how electromagnetic energy can be explained by treating the spread of energy over a range of wavelengths.
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