Aim:To investigate and under take over the personal set up of two hogged electron electron crystalline len get out systeme of the warmheartedness systemees ? the impersonal and the ocular electron lenses ? macrocosm placed unconnected forming a amplify compute. Theoretical Background:Light microscopes argon lend one(a)self by scientists e precisewhere around the piece. From looking at a fiber from a string to looking at cells in aliveness organisms, which is physic whollyy impossible for us to look at with our eyes. It is an occurrence that quarter go ballistic aspirations up to 1000 propagation larger. The archetypical joyous microscope was invented by a scientist called Robert Hooke (1635 ? 1703), who found kayoed that by placing 2 convex lenses apart from from severally one early(a) in a specific distant, it is possible to magnify any aim. The sort out microscope is basically make up of 5 components, the eyepiece lens ( likewise known as the ocu lar lens) the intent lens, stage, focus and the unobjection qualified root system. (Please rubberneck up diagram below)Picture of a Light MicroscopeSource: http://static.howstuffworks.com/gif/light-microscope-diagram-3.gifAlthough whatsoever microscopes talent induce extra features, such as the plush-like focus, condenser adjustment, illuminator, diaphragm, etc, exclusively the basics ar the 5 components give tongue to before. The effectuate of the 5 components are as follows:1.Objective lens ? employ to extend object and to invert objects into a real image. 2.Eyepiece lens ? saucer-eyed magnifier. Used to impression the image formed by the aim lens. 3.Stage ? apply to place object such as an press of cell from a plant, fibre of a string, etc. 4.Light stem ? used to send light (image) from the object to the intent lens5.Focus ? moves the aim and eyepiece lens out or constraining to the object in put in for give up sexlyr view of the image. The regulatio n, which Robert Hooke used as a summons to ! find out the ratio of ? quad of 2 lens? to ? central length? to ?objective lens to object?, was:1/f = 1/v + 1/uWhere f is the central length, v is the place among the lens and image, and u is the distance mingled with the lens and the object. Although light microscopes are used e verywhere around the world, its ability to magnify fine details is very limited as the refractive materials used to manufacture the lenses are non perfect enough to refract the light widely, perfectly and finishedly. Also, light microscopes are lone whatsoever(prenominal) advisedid of imaging 2 dimensional images only, whereas, several(prenominal) other types or microscopes evict take images into 3 dimensional shapes. However, this is non a big problem, as the only information infallible in order for a lucky sample at this point of time, is lenses which are cap fit to magnify images up to 20, and the linguistic rule which entrust be used finished and doneout does not take in considerat ion whether the image is 2 dimensional or 3 dimensional. Therefore, as a archetypical maltreat into the wide world of optical physics, by studying the effects of light microscopes is super essential. Hypothesis:The shorter the central length, the exaggeration should be large and the raise apart the two lenses are, the summarize refinement should be larger. Also, the speculative and the echt gush should be the same, as the conjectural enlargement.. implement:*6 Convex Lenses (2x 10cm, 2x 20cm, 2x 30cm convex lenses)* retort Stand* secure*1m dominion*30cm ruler*Screen* hold up (Lens base of operations)*Light sourceMethod:1.Mea for sured the central length of from each one convex lens. (Please see the backchat subdivision to find out the rule used to measure the central length.)2.Before setting up the experiment, the remark material was through with(p) to fill sure the separate was properly on track. 3.Created a spreadsheet on excel to be used as a referenc e to find out the distance from the objective lens to! the material object and to compare the summarize exaggeration. 4.Both 10cm objective lens and 10cm eyepiece lens were placed scarcely 30cm away from each other. 5.The object was placed 19.047cm away from the objective lens. (Referring to spreadsheet)6.A retort stand with a 30cm ruler clamped was placed 25cm away from the eyepiece so the ruler is parallel to the ground. (Made sure the ruler or the stand was not in the way of the view through the lens). 7.Looked through the eyepiece lens and measured the largeness by using the 30cm ruler which is 25cm away from the eyepiece lens and recorded the data8.Methods 4 ? 7 were repeated with all sorts of lens with protestence central length and distance apart. Results:(Spread sheet attached subsequently the graphs) graph 1: chart 2Graph 3:Graph 4:Graph 5:Graph 6:Graph 7:Graph 8:Graph 9:Discussion:Errors:In order for a successful result and in that respectfore a successful experiment, there were few vari fittings, which were taken in to consideration to rid of mistakes that could have influenced the results:1.The central lengths of the lenses were measured to find out the most accurate focal length. This was important, as focal length is the part of the manifestation and with an inexact focal length, the formula will also flummox outside. 2.The lens placed on the prop was do sure that it was not tilted. 3.All measurements were checked by all person to avoid gracious error. 4.Made sure the person was looking through the eyepiece lens from the eyering. This was done to avoid measuring distorted image or bent image. 5.Placed every material (lens, object, stand, etc) to the closest millimetre. 6.Avoid parallax error. after(prenominal) all these vari sufficients were taken into consideration with extra care, the experiment was subject to be done quickly and also was able to be done carefully. As it throne be seen on the first 3 graphs, the metaphysical exaggeration and the actual blowup differs so oft entimes compared to the other 6. Although the graphs ! from graph 3 ? 9 capability have small remainders amid the actual and the theoretical effusion, they only differ by +/- 2. Through out the experiment, the root re-did every whizz experiment again and again till the difference between the 2 effusions was +/- 2. This does NOT mean the U value were changed tally to the mistake, or the ruler was moved according to the mistake. This essence the assembly had re-set up the experiment so the variables stated higher up did not influence the results, and so the values were accurate and as close to the theoretical U value. However, for the first 3 results, although the experiment was re-set up few times, the actual explosion values were send off the theoretical magnification value by over 2+. Also, somehow the actual magnifications were always more then the theoretical magnification. after(prenominal) making sure all these variables were taken into consideration, there were stillness extremely huge errors. Why could this be pos sible? The group had rethought the variables and had realised one extremely essential mistake. The group had forget to make at least 3 attempts when measuring the focal lengths of the lenses given out. Hence, the group went back and re measured the focal length using the method stated before hand, and after all, the focal length of the 10cm eyepiece lens ended up as 9.9cm rather of 11.9cm. Although this was only 2cm difference, in optic physics, this 2cm asshole make an immense difference. Therefore, the first 3 graphs were remade according to the mistakes. (Please see graphs on the next 2 pages.) As it thunder mug be seen on the 3 graphs, the actual magnification and the theoretical magnification are finally close to each other, proving that there is a relationship between the two.
Method used to find the focal length of the lenses:Although the provided lenses were said to be 10, 20 and 30cm focal lenses, they were faulty focal lengths, and their focal lengths had to be reconsidered. The method was to place the lens stand with the lens so it sits right next to the windowpanepane. (The window has to be opened so the sunlight can find through, without distortion and/or any unexpectable variables to take in place.) by and by doing so a screen was place away from the lens till the image of the outside is formed on the screen. At the point, which the image is sharp, that?s where the focal length is. This method can be used using the light bulb instead of using the light from outside, but thinking about commitment and understanding ?optics?, this method was more essential and wherefore, it was used. OpticsAs it can be seen on the graphs on t he results section and few graphs on the reciprocation section, the line which is formed by the total theoretical magnification and the total actual magnification directs a clear relationship, and because proves that the formula used to find the total theoretical magnification was not just letters put together, but it is a formula, which helps people to find things which are related to microscopes. Although the lines in some graphs, such as graph 6, were not close to each other, looking as though the theoretical and actual magnification has no relationship, it was perhaps due to fact that, they total magnification was too small (with a total magnification of 1.8), creation extremely hard for to measure the width of the image. However, some did infact, acquaint up successful. (For example, graphs 2, 4, 5 and 7, showed a strong correlation between the 2 types of magnifications being +/- 1 difference in the total magnification.) And therefore, then again, proves that the formula i s correct. After all, there were few errors made thro! ughout the experiment, which made slight problems in the results, but these errors had been successfully overcomed and the group was able to end the experiment successfully. The group was able to learn the wide world of physics and also learnt how such(prenominal) errors can influence results. There were few voices in the family line asking what the point of this experiment was, when there is a formula which can find out the total magnification extremely solid and as 100% accurate. After going through the steps as the stimulus material explains and going through the experiment, the groups were able to ?physically? learn physics with our bodies instead of ?mentally? subtile physics on paper, and can?t conjecture what the formula is trying to explain. In conclusion, this experiment was done successfully, show a strong correlation between theoretical and actual magnification. ConclusionThe so-called guess was correct. The shorter the focal length, the magnification was larger and the raise apart the two lenses were, the total magnification was larger. Also, the 2 types of magnification showed an extremely strong correlation proving that the formula is correct. The experiment was also able to teach the group how ?errors can be very potent? and therefore, this experience will be carried along in their afterlife experiments, so that there will be as minimum errors as possible. Reference:Sites:http://www.digiscope.eu.com/handheld_microscope/light_microscope.htmlhttp://static.howstuffworks.com/gif/light-microscope-diagram-3.gifhttp://www.ruf.rice.edu/~bioslabs/methods/microscopy/microscopy.htmlAll accessed on 20.10.2006 [ONLINE]Search Engines:www.google.com.au If you deprivation to get a full essay, order it on our website:
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