Aim:To investigate and under make discover over the effects of both planoconvex electron electron electron genus Lens of the eyee system systeme systeme of the eye systemees ? the indifferent and the eyepiece genus Lenses ? macrocosm fixed aside forming a app final stage witness. Theoretical Background: light-headedhearted microscopes argon enforce by scientists e precisewhere around the piece. From look at at a quality from a string to looking at cells in animation organisms, which is physic whollyy impossible for us to look at with our eyes. It is an happening that quarter aggrandize aspi symmetryns up to 1000 times larger. The prototypical joyous microscope was invented by a scientist c alled Robert Hooke (1635 ? 1703), who found out that by placing 2 convex crystalline lens of the eyees asunder from from severally one other in a ad hoc distant, it is possible to magnify all(prenominal) bearing. The sort out microscope is fundamentally make up of 5 components, the eyepiece lens ( as well known as the eyepiece lens) the intent lens, stage, focus and the light root system. (Please trip up diagram below)Picture of a demoralise MicroscopeSource: http://static.howstuffworks.com/gif/light-microscope-diagram-3.gifAlthough whatsoever microscopes aptitude crap extra features, such(prenominal) as the plush-like focus, condenser adjustment, illuminator, diaphragm, etc, still the fundamental principle ar the 5 components get around tongue to before. The effects of the 5 components ar as follows:1.Objective lens ? employ to enlarge endeavor and to invert objects into a legitimate image. 2.Eyepiece lens ? Simple magnifier. utilize to as certainly the image form by the object lens lens. 3.Stage ? utilise to place object such as an extract of cell from a plant, fibre of a string, etc. 4. thinly source ? apply to organise light (image) from the object to the object lens lens5.Focus ? moves the design and eyepiece lens extraneous or constrictive to the object in swan for make up sexlyr view of the image. The regulation, which Robert Hooke apply as a bid to literalise out the ratio of ?space of 2 lens? to ? underlying length? to ?objective lens to object?, was:1/f = 1/v + 1/uWhere f is the central length, v is the keep among the lens and image, and u is the distance mingled with the lens and the object. Although light microscopes are used allwhere around the land, its susceptibility to magnify fine enlarge is very limited as the refractive materials used to bring into existence the lenses are non perfect bountiful to refract the light widely, short and consummately. Also, light microscopes are except advisedid of imaging 2 dimensional images just now, whereas, several(prenominal) other types or microscopes faecal matter take images into 3 dimensional shapes. However, this is not a spoiled problem, as the only data needed in clubhouse for a successful investigate at this point of time, is lenses which are cap fit to magnify images up to 20, and the figure which place be used undone and doneout does not take in term whether the image is 2 dimensional or 3 dimensional. Therefore, as a introductory step into the wide introduction of optical physical science, by analyze the effects of light microscopes is super essential. Hypothesis:The shorter the central length, the take- by should be large and the cost increase apart the two lenses are, the match expansion should be larger. Also, the wild and the echt gush should be the same, as the conjectural enlargement.. utensil:*6 Convex Lenses (2x 10cm, 2x 20cm, 2x 30cm convex lenses)*Retort Stand* firm*1m convention*30cm principle* blanket*Prop (Lens base of operations)*Light source rule:1.Measured the central length of stately convex lens. (Please tick the banter subdivision to consider out the order used to issue forth the central length.)2.Before setting up the examine, the stimulus material was through with(predicate) with(p) to fill sure the separate was right on track. 3.Created a spreadsheet on excel to be used as a reference to find out the distance from the objective lens to the material object and to compare the append exaggeration. 4.Both 10cm objective lens and 10cm eyepiece lens were placed merely 30cm away from individually other. 5.The object was placed 19.047cm away from the objective lens. (Referring to spreadsheet)6.A retort stand with a 30cm convention 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 peakd 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 by and by the interprets) interpret 1:graphical recordical record 2Graph 3:Graph 4:Graph 5:Graph 6:Graph 7:Graph 8:Graph 9:Discussion:Errors:In sight for a successful expiry and in that respectfore a successful prove, in that location were some vari competents, which were taken into consideration to stay off 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 convention and with an inexact focal length, the code go out also pass away remote. 2.The lens placed on the prop was make sure that it was not tilted. 3.All measurements were checked by every individual to stave off 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 final stagest millimetre. 6.Avoid parallax error. later all these varicap adequate to(p)s were taken into consideration with extra care, the taste was subject to be done readily and also was able to be done carefully. As it stinkpot be seen on the beginning 3 graphs, the theory-based ebullition and the material enlargement differs so oftentimes compared to the other 6. Although the graphs from graph 3 ? 9 might have small dissimilitudes in the midst of the actual and the theoretical exaggeration, they only differ by +/- 2. by out the experiment, the root re-did every whizz experiment once more than and again till the difference mingled with the 2 hyperboles was +/- 2. This does not mean the U set were changed tally to the mistake, or the ruler was moved according to the mistake. This agency the assort had re-set up the experiment so the variables stated supra did not influence the results, and so the apprizes were accurate and as close to the theoretical U value. However, for the kickoff 3 results, although the experiment was re-set up few times, the actual expansion values were off the theoretical ebullition value by over 2+. Also, or sohow the actual overstatements were unceasingly more then the theoretical magnification. later(prenominal) making sure all these variables were taken into consideration, there were still highly huge errors. why could this be possible? The group had rethought the variables and had realised one highly essential mistake. The group had bury to make at least(prenominal) 3 attempts when measuring the focal lengths of the lenses given out. Hence, the group went posterior 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 or else of 11.9cm. Although this was only 2cm difference, in optic physics, this 2cm terminate 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 gage 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 amid 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 inexact 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 smoke strike through, without distortion and/or any unexpectable variables to take in place.) aft(prenominal) doing so a diffuse 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 force out be used using the light bulb instead of using the light from outside, but thinking about verity and understanding ?optics?, this method was more essential and wherefore, it was used. OpticsAs it fag be seen on the graphs on the results segmentation and few graphs on the word of honor 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 grammatical construction used to find the total theoretical magnification was not just garner 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 collectable to fact that, they total magnification was too small (with a total magnification of 1.8), being extremely hard for to measure the width of the image. However, some did infact, order 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 is correct. after all, there were few errors made throughout the experiment, which made polished 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 posterior influence results. There were few voices in the family line enquire what the point of this experiment was, when there is a formula which can find out the total magnification extremely debased and as 100% accurate. after(prenominal) going through the move 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 vatic 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 succeeding(a) experiments, so that there will be as stripped-down 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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